Date post: | 19-Oct-2015 |
Category: |
Documents |
Upload: | alexandros-kokkosis |
View: | 12 times |
Download: | 0 times |
of 15
*Correspondence should be addressed to: Dr. Dowluru SVGK Kaladhar. Department of Biochemistry/Bioinformatics, GIS,
GITAM University, Visakhapatnam-530045, AP, India. E-mail: [email protected]
ISSN: 2152-5250 186
Original Article
Functional Analysis and Molecular Docking studies of
Medicinal Compounds for AChE and BChE in
Alzheimer's Disease and Type 2 Diabetes Mellitus
Dowluru SVGK Kaladhar*, Nagendra Sastry Yarla and N. Anusha
Department of Biochemistry/Bioinformatics, GIS, GITAM University, Visakhapatnam-530045,
AP, India
[Received May 5, 2013; Revised June 13, 2013; Accepted June 14, 2013]
ABSTRACT: Acetylcholinesterase and Butyrylcholinesterase share unravelling link with components of
metabolic syndromes that's characterised by low levels of HDL cholesterol, obesity, high fast aldohexose
levels, hyper-trigliceridaemia and high blood pressure, by regulation of cholinergic transmission and
therefore the enzyme activity within a living system. The phosphomotifs associated with amino acid and
tyrosine binding motifs in AChE and BChE were known to be common. Phylogenetic tree was constructed
to these proteins usinf UPGMA and Maximum Likelihood methods in MEGA software has shown
interaction of AChE and BChE with ageing diseases like Alzheimer's disease and Diabetes. AChE has
shown closely related to BChE, retinol dehydrogenase and -polypeptide. The present studies is also accomplished that AChE, BChE, COLQ, HAND1, APP, NLGN2 and NGF proteins has interactions with
diseases such as Alzheimer's and D2M using Pathwaylinker and STRING. Medicinal compounds like
Ortho-7, Dibucaine and HI-6 are predicted as good targets for modeled AChE and BChE proteins based on
docking studies. Hence perceptive studies of cholinesterase structure and the biological mechanisms of
inhibition are necessary for effective drug development.
Key words: AChE, BChE, Protein interactions, Phylogeny, Docking
Acetylcholinesterase (acetylhydrolase or AChE) could
be a serine protease that hydrolyzes acetylcholine that
acts because the neurochemical in varied species [1, 2].
AChE (Acetylcholinesterase) and BChE
(Butyrylcholinesterase) belongs to carboxylesterase
family of enzymes. AChE is principally found in several
varieties of conducting tissue that serves to terminate
junction transmission [3, 4, 5]. Biogenic amines will
intervene many varieties of living thing communication
in cellular organisms and somewhat evidence has
indicated that biogenic amines produce intracellular
responses aside from by triggering the protein production of second messengers [6].
AChE and BChE involve in control cholinergic
transmission and also the proteinase activity and
develops Alzheimers as a result of production of the -amyloid macromolecule [7]. AChE catalysis the
hydrolysis of acetylcholine of neurotransmitter to acetate
and choline at cholinergic nerve terminals and terminates
the action of AChE on postsynaptic receptors. BChE
involves interactions inside the system in three different
enzymatic activities in its structures like AChE, aryl
acylamindase and proteinase [8].
Neuronic complications taking place in D2M
(Diabetes Mellitus Type 2) is influenced as a result of AChE activity by membrane surface development
characterised by morphological changes related to
Volume 4, Number 4; 186-200, August 2013
D. S. K. Kaladhar et al AChE and BChE studies in Alzheimers and D2M
Aging and Disease Volume 4, Number 4, August 2013 187
minimized motor and sensory conductivity velocities and
is being corrected by hypoglycemic agent treatment [9].
The insertion of membrane proteins into the membrane
core is also passionate about transmembrane potential
that will have an effect on lipid-protein interaction [10]
and these activities emerge in association with plaques
and tangles in AD (Alzheimer's disease). This
pathological cholinesterase with altered properties of
AChE and BChE turn out additional severe cases in
increasing variety of plant tissue and neurocortical
amyloid made cerebral cortex amyloid made neurotic
plaques and neurofibrillary tangles in manifestations of
AD [11].
AChE is found exuberant in brain, muscle, and
blood corpuscle membrane, whereas BChE has higher
activity in liver, intestine, heart, excretory organ and
respiratory organ. AChE and BChE contribute 65
percent aminoalkanoic acid sequence similarity and have
connected molecular forms despite of being merchandise
of various genes lying on human chromosomes 7(7q22)
and 3(3q26) [12]. The active site within the structure of
human BChE gap is schematized and therefore the
peripheral ionic site (PAS) is found at the mouth of the
gorge. Asp70 and Tyr332 residues of PAS are initial
binding of charged substrates and have a bond that
controls the operate design of the BChE situation gorge
[13]. BChE could be a major detoxification protein of
cocain in plasma with inactive metabolites made, like
ecgonine methyl ester and benzoic acid, are rapidly
excreted by kidney. A signal of cocain toxicity includes
elevated vital sign, pathology grand-mal seizure and
stroke. BChE protects from deadly effects of cocain by
management of purified human serum [14]. AD and
D2M occur with increasing frequency as age advances
and disease development results in risk of onset of
another disease.
In the risk of AD and D2M, a range of mechanisms
has been postulated like metabolic abnormalities of
insulin resistance, dyslipidemia, high blood pressure,
hypertension, hyperglycaemia, disturbing synaptic
plasticity learning and memory [15]. BChE is related to
interstitial tissue cells, epithelial tissue cells and neurons
BChE which will be known from AChE in its kinetic
response to concentration of acetylcholine. BChE
hydrolysis high concentration of acetylcholine and is
related to interstitial tissue cells [16]. In cell cultures and
epidemiologic surveys, agents such as herbal extracts
with inhibitor property and NSAID (nonsteroidal anti-
inflammatory drugs) showed protecting impact against
AD pathology [17, 18, 19].
Exposure to organophosphate pesticides disrupts neurotransmission by inhibiting conjugation AChE
resulting in acetylcholine accumulation within the
junction and neural over stimulation result in death due
to cardiovascular and respiratory collapse [20].
Inhibition of AChE and BChE by organophosphorus
compounds take in a very progressive manner and also
the reactivation of phosphorylated accelerator are often
done by treating with sturdy nucleophilic agents like
oximes [21]. More than 10,000 molecules of
acetylcholine are often cleaved per second in brain by
AChE and BChE. AChE knockout mouse survives for
many weeks in absence of AChE as a result of AChE is
remunerated by BChE and provides backup and
regulates cholinergic transmission that shows the precise
cholinergic pathways regulated by BChE in brain of
patients with AD [22].
Most of the proteins within the cell move with
alternative protein molecules so a lot of essential for
cellular method like cellular motion, signal transduction,
transportation and most restrictive mechanism that are
mediate by protein-protein interaction [23]. These
proteins will have measurable effects in altering the
kinetic properties of the cellular components. These
transient altering are consequence of protein kinases,
protein phosphotases, acyltransferases, glycosyl
transferases, etc [24]. Experimental knowledge on
physical protein-protein interactions are largely hold on
and a STRING (Search Tool for Retrieval of INteracting
Gene) info provides data on useful links between
proteins [25]. Signalink info may be a uniformly curetted
info of eight major signalling pathways [26]. HPRD
(Human Protein Reference Database) is internet
primarily based community[27, 28], a unique
comprehensive protein data resource that depicts
completely different options of proteins like domain
structure, post-translational modifications, tissue
expression, protein-protein interactions, enzyme-
substrate relationships and molecular function.
Protein-Protein interactions play a crucial role in
identification of metabolic syndrome pathways, provides
advancements from the past for understanding molecular
options for vital network topologies in biological
systems [29]. AChE and BChE are often found in blood
and is related to options of the metabolic syndrome [30].
Central and involuntary nervous systems regulate
immediate variations with AChE and BChE activity
that's crucial with chemical change properties and
general functions. Factor and haplotype variations within
the enzyme genes were related to changes in blood. Both
AChE and BChE activities brings changes in plasma
lipid and lipoprotein concentrations, obesity and
additional elements of the metabolic syndrome.
The MetS (metabolic syndrome) is characterised by
abdominal obesity, low levels of high-density lipoprotein (HDL) sterol, elevated fast aldohexose levels and hyper-
trigliceridaemia with cardiovascular disease [31, 32]
during involvement of AChE and BChE in lipid
D. S. K. Kaladhar et al AChE and BChE studies in Alzheimers and D2M
Aging and Disease Volume 4, Number 4, August 2013 188
metabolism. BChE, AChE and Neuroligin structurally
belong to a family of alpha beta hydrolase fold and are
inferred from the similar structural patterns [33].
Diabetes, Obesity and Neurological disturbances show
co-occurrence by activity a comparative analysis with
NLGN2 (Neuroligin) a protein belonging to the same
family, alters the signal transduction of neurons, a
possible reason for Neurological disturbances.
The brain of mammals contains two major forms of
cholinesterases, AChE and BChE have similar perform
to enzymatic differences however show variations
genetically, structurally and for and for their kinetics
[34]. AChE activity decreases progressively whereas
BChE activity shows some increase within the brain of
AD patients.
Cholinesterase inhibitors (ChEIs) are efficacious for
mild to moderate AD exert 3 main actions: inhibit
enzyme (ChE), increase extracellular levels of brain
neurotransmitter (ACh) and improve psychological
feature processes [35]. Severely and selectively damaged
central cholinergic systems are concerned
neurodegenerative diseases like Alzheimer's disease and
dementia with Lewy bodies [36, 37].
MATERIALS AND METHODS
AChE and BChE are interlinked with various proteins
related to AD and D2M. To find out the protein
interactions, an interaction profile studies and
experimental graphs has been studied using STRING
database.
Sequence retrieval
The National Centre for Biotechnology Information
advances science and health by providing data access to
biomedical and genomic information. The NCBI stores
genome sequencing data in GenBank and an index of
biomedical research analysis articles in PubMed and
PubMed Central, in addition as alternative information
relevant to biotechnology. All these databases are
accessible on-line through the Entrez search engine.
The interaction profile data from HPRD has
presented good signaling profile and hence protein
sequences related to these proteins has been retrieved for
further studies.
The molecular weight of AChE is 67376 Da present
in gene map locus at 7q22. AChE interacts with various
molecules such as Proline rich membrane anchor 1,
Collagen-like tail subunit (single strand of homotrimer)
of asymmetric acetylcholinesterase, HAND1, Ligatin, Laminin, alpha 1, Laminin beta 1, Collagen, type IV,
alpha 1, Amyloid beta A4 protein. The sequence of
AChE retrieved for modelling of receptor is:
>AChE sequence MRPPQCLLHT PSLASPLLLL
LLWLLGGGVG AEGREDAELL VTVRGGRLRG
IRLKTPGGPV SAFLGIPFAE PPMGPRRFLP
PEPKQPWSGV VDATTFQSVC YQYVDTLYPG
FEGTEMWNPN RELSEDCLYL NVWTPYPRPT
SPTPVLVWIY GGGFYSGASS LDVYDGRFLV
QAERTVLVSM NYRVGAFGFL ALPGSREAPG
NVGLLDQRLA LQWVQENVAA FGGDPTSVTL
FGESAGAASV GMHLLSPPSR GLFHRAVLQS
GAPNGPWATV GMGEARRRAT QLAHLVGCPP
GGTGGNDTEL VACLRTRPAQ VLVNHEWHVL
PQESVFRFSF VPVVDGDFLS DTPEALINAG
DFHGLQVLVG VVKDEGSYFL
VYGAPGFSKD NESLISRAEF LAGVRVGVPQ
VSDLAAEAVV LHYTDWLHPE DPARLREALS
DVVGDHNVVC PVAQLAGRLA AQGARVYAYV
FEHRASTLSW PLWMGVPHGY EIEFIFGIPL
DPSRNYTAEE KIFAQRLMRY WANFARTGDP
NEPRDPKAPQ WPPYTAGAQQ YVSLDLRPLE
VRRGLRAQAC AFWNRFLPKL LSATASEAPS
TCPGFTHGEA APRPGLPLPL LLLHQLLLLF
LSHLRRL
The molecular weight of BChE is 68418 Da and
present at gene map locus of 3q26.1-q26.2. It expresses
in Brain, plasma and Fetus. It interacts with proteins
such as Collagen-like tail subunit (single strand of
homotrimer) of asymmetric acetylcholinesterase. The
sequence of BChE retrieved for modelling of receptor is:
>BChE sequence
MHSKVTIICI RFLFWFLLLC MLIGKSHTED
DIIIATKNGK VRGMNLTVFG GTVTAFLGIP
YAQPPLGRLR FKKPQSLTKW SDIWNATKYA
NSCCQNIDQS FPGFHGSEMW NPNTDLSEDC
LYLNVWIPAP KPKNATVLIW IYGGGFQTGT
SSLHVYDGKF LARVERVIVV SMNYRVGALG
FLALPGNPEA PGNMGLFDQQ LALQWVQKNI
AAFGGNPKSV TLFGESAGAA SVSLHLLSPG
SHSLFTRAIL QSGSFNAPWA VTSLYEARNR
TLNLAKLTGC SRENETEIIK CLRNKDPQEI
LLNEAFVVPY GTPLSVNFGP TVDGDFLTDM
PDILLELGQF KKTQILVGVN KDEGTAFLVY
GAPGFSKDNN SIITRKEFQE GLKIFFPGVS
EFGKESILFH YTDWVDDQRP ENYREALGDV
VGDYNFICPA LEFTKKFSEW GNNAFFYYFE
HRSSKLPWPE WMGVMHGYEI EFVFGLPLER
RDNYTKAEEI LSRSIVKRWA NFAKYGNPNE
TQNNSTSWPV FKSTEQKYLT LNTESTRIMT
KLRAQQCRFW TSFFPKVLEM TGNIDEAEWE WKAGFHRWNN YMMDWKNQFN DYTSKKESCV
GL
D. S. K. Kaladhar et al AChE and BChE studies in Alzheimers and D2M
Aging and Disease Volume 4, Number 4, August 2013 189
MEGA
MEGA (Molecular Evolutionary Genetic Analysis) is an
integrated tool used for conducting automatic and
manual sequence alignment, inferring phylogenetic trees,
mining web-based databases, estimating rates of
molecular evolution, inferring ancestral sequences, and
testing evolutionary hypotheses.
ClustalW
ClustalW is a widely used system for aligning any
number of homologous nucleotide or protein sequences.
ClustalW uses progressive alignment techniques for
multi-sequence alignments that are useful to construct
phylogenetic tree.
Construction of phylogenetic tree
Phylogenetic relationships of genes and the organisms
usually are presented in a tree like form in cladistics. The
sequences have shown homology with the sequences
present in GenBank. The sequences of AChE
(AAH94752), retinal dehydrogenase (AAC09250), -polypeptide (AA126151), BChE (AAH08396) and tau-
protein (AAA57264) has been retrieved from GenBank
and constructed phylogeny in MEGA software using
Maximum Likelihood and UPGMA Methods.
Signalink
PathwayLinker identifies and visualizes the first
neighbour interactor network of the queried proteins,
analyzes the signaling pathway of the proteins in subnet,
and provides links to online web resources. Some of the
biomedical research often focuses on altering the
functions of selected proteins. PathwayLinker can assist
experimental work by linking the queried proteins to
signaling pathways through protein-protein and/or
genetic interactions.
Human Protein Reference Database (HPRD)
The HPRD is a centralized tool that integrates data
bearing on domain design, post-translational
modifications, interaction networks and association for
every macromolecule within the human protein.
STRING (Search Tool for the retrieval of interacting
Genes/Proteins)
STRING is a well known database for predicting protein
interactions and embrace physical (direct) and
purposeful (indirect) associations between proteins.
STRING integrates interaction knowledge from the
sources for an outsized range of organisms and transfers
information between these organisms wherever
applicable.
Molecular modelling and Ligand design
The sequences of AChE and BChE are retrieved from
HPRD and modelled for evaluation of docking
parameters with the ligands. The sequences have been
submitted to Swiss-model and the protein molecules
have been saved as .pdb format. Medicinal compounds
like Huperzine, Rivastigmine, Ambenonium, Ortho-7,
Donepezil, Pyridostigmine, Galanthamine, AChE
inhibitor substrate, HI-6 have been selected from
literature to test the activity against modelled AChE
molecule. Medicinal compounds like Chlorpyrifosoxon,
1-anilino-8-naphthalene sulfonic acid, Dibucaine,
Procainamide, Benzoylcholine, Propionyl thicholine,
Acetyl thiocholine, Dialkylphenylphosphates, Tetra ethyl
ammonium are selected to test the activity against
modelled BChE molecule. These 2D ligands have been
constructed using ChemSketch, optimised and saved as
.mol format. The 2D ligands in .mol format has been
opened in Hyperchem, and the 3D structures has been
saved as .pdb format.
Docking
Docking is the process of bringing one molecule in
vicinity with an another molecule. The present research
work is conducted the drug molecules to be docked with
the modelled receptors such as AChE and BChE.
Docking is conducted using free softwares such as iGemdock v2.0 and Hex v6.0, and a commercial
software such as Autodock v4.2.
iGemdock v2.0
iGEMDOCK (iGeneric Evolutionary Method DOCKing)
for molecular docking is a program for computing a
ligand conformation and orientation relative to the active
site of target protein. GEMDOCK has pharmacophore-
based scoring function and the results performed based
on the homology model.
Autodock v4.2
AutoDock is a suite of automated and commercial
docking tool designed to predict small molecules
docking to a receptor (diseased or useful components
of cell).
D. S. K. Kaladhar et al AChE and BChE studies in Alzheimers and D2M
Aging and Disease Volume 4, Number 4, August 2013 190
Hex v6.0
Hex is an interactive protein docking and molecular
superposition program. The instructions from Hex is
understands as protein or DNA structures in PDB format.
It can also read small-molecule as SDF files.
Figure 1: Clade of AChE and BChE with Alzheimers and D2M (UPGMA Method)
RESULTS
Sequencing studies of genome and proteome have
provides an incredible landmark within the history of
biology. A significant role for sequences of DNA is to
encode the sequences of proteins that that are
participating in essentially all processes. Proteins are
flexible, vibrant and extremely complex molecules
molecules in a very constant state of modification
through initiating and driving interactions with several
molecules leads to different cellular states.
Phylogenetic tree was constructed to the proteins
showing interaction with AChE and BChE involved in
ageing diseases in MEGA. Phylogenetic tree is
constructed using UGPMA from MEGA software
(UPGMA Method) and relatedness of the proteins was
shown in Figure 1.
The most challenging part of the phylogeny
construction involves comparing the nearest relatives
with specific domain content. Phylogenetic tree was
constructed to the proteins showing interaction with
AChE and BChE involved in agening diseases with
Maximum Likelihood method in MEGA (Figure 2). The
results predicted that AChE is closely related to retinol
dehydrogenase and -polypeptide. AChE is also shown close relationship with BChE and tau-protein.
The interaction between AChE and BChE with other
proteins like COLQ, APP etc was retrieved from
Pathway linker database by submitting the query in
search box and the result is represented in Figure 3.
Figure 2: Phylogentic Tree Construction using MEGA (Maximum Likelihood Method)
D. S. K. Kaladhar et al AChE and BChE studies in Alzheimers and D2M
Aging and Disease Volume 4, Number 4, August 2013 191
Figure 3: Pathway Linker Results for AChE and BChE
HPRD for AChE and BChE Protein interaction
In HPRD, the information about the protein-protein
interaction, post-translational modifications, enzyme-
substrate relationships and disease association are
retrieved and represented in Figure 4.
The query protein related to AChE has been
uploaded to HPRD Phosphomotif finder and results were
retrieved and protein contains 152 Serine kinase /
phosphatase motifs. The results are predicted that
PhosphoMotifs of AChE is related to GSK-3, ERK1, ERK2, CDK5 substrate motif , G protein-coupled
receptor kinase 1 substrate motif, X DNA dependent
Protein kinase substrate motif, Casein Kinase I and II
substrate motifs GSK-3, ERK1, ERK2, CDK5 substrate
motif, PKA kinase substrate motif, PKC kinase substrate
motif, Calmodulindependent protein kinase II substrate
motif, Growth associated histone HI kinase substrate
motif, PP2C delta substrate motif, b-Adrenergic
Receptor kinase substrate motif, Dual specificity protein
phosphatase 6 substrate motif, MAPK 11, 13, 14 Kinase
substrate motif, Pyruvate dehydrogenase kinase substrate
motif, Pim1 kinase substrate sequence, LKB1 Kinase
substrate motif, NIMA kinase substrate motif, AMP-
activated protein kinase substrate motif, Chk1 kinase
substrate motif.
Figure 4: Interaction report of Acetylcholinesterase
D. S. K. Kaladhar et al AChE and BChE studies in Alzheimers and D2M
Aging and Disease Volume 4, Number 4, August 2013 192
Figure 5: Interaction report of Butyrylcholinesterase
In the query protein AChE there are 16 Serine
binding motifs as WW domain binding motif, 14-3-3
domain binding motif, MDC1 BRCT domain binding
motif and Plk1 PBD domain binding motif. For the given
query BChE information about protein-protein
interaction, disease association, post-translation
modification, enzyme substrate relationships are
retrieved using HPRD (Figure 5).
The number of serine kinase/ phosphatase in the
protein BChE is retrieved. There are 157 Serine kinase /
phosphatase motifs such as AMP-activated protein
kinase substrate motif, Casein Kinase I and II substrate
motif, PKA kinase substrate motif, PKC kinase substrate
motif, Chk1 kinase substrate motif, Calmodulin-
dependent protein kinase II substrate motif, G protein-
coupled receptor kinase 1 substrate motif, PP2C delta
substrate motif, Dual specificity protein phosphatase 6
substrate motif, b-Adrenergic Receptor kinase substrate
motif, G protein-coupled receptor kinase 1 substrate
motif, GSK-3, ERK1, ERK2, CDK5 substrate motif and
CLK1 kinase substrate motif.
Figure 6: AChE and BChE Interactions shown in STRING Database
D. S. K. Kaladhar et al AChE and BChE studies in Alzheimers and D2M
Aging and Disease Volume 4, Number 4, August 2013 193
Figure 7: Protein Interactions with genes responsible to metabolic syndrome
The query protein BChE was submitted in the
phosphomotifs finder and the number of serine binding
motifs was retrieved and there are 12 Serine binding
motifs such as MDC1 BRCT domain binding motif, Plk1
PBD domain binding motif and WW domain binding
motif.
The proteins AChE and BChE were given in
STRING database and its interaction with various
proteins were retrieved where it shows interaction with
some of the proteins like NGF, COLQ and HSPQ2
(Figure 6 and 7).
The proteins AChE and BChE were given in
STRING database and its interaction with various proteins were retrieved, where it shows direct
interactions with some of the proteins like NGF (linked
to Alzheimer's disease), COLQ (associated with
Congenital myasthenic syndromes (CMS)), NGF (cause
of Alzheimers disease and atherosclerotic cardiovascular
disease), NLGN2 ( associated with Alzheimers disease
and autism) , etc (Figure 8).
Docking is a mechanism used to increase enzymesubstrate specificity and govern the binding of kinases
and phosphatases to each other and other effectors that
provides an understanding of proteinprotein interaction permitting fundamental insight to the researchers.
Docking surfaces encode specific information about
kinase or phosphatase interactions in the framework of
many related peptide motifs. Docking results with some ligands has been presented in Figure 9.
D. S. K. Kaladhar et al AChE and BChE studies in Alzheimers and D2M
Aging and Disease Volume 4, Number 4, August 2013 194
Figure 8: AChE and BChE interaction mapping
Table 1. Modelled AChE and its Ligands Docking (AutoDock)
Properties Hupe
rzine
Rivas
tigm
ine
Amben
onium
Ortho-7 Donep
ezil
Pyrid
Ostigm
Ine
Galan
Tham
ine
AChE
inhibitor
substrate
HI-6
Binding- energy -3.73 -3.9 0.96 -3.3 -4.58 -3.36 -4.29 -2.12 -6.76
Ligand-
efficiency
-0.21 -0.22 0.03 -0.13 -0.16 -0.26 -0.15 -0.21 -0.32
Inhib-constant 1.83 1.38 - 3.79 436.93 3.44 711.8 28.14 11.12
Inhib-constant units
Mm Mm - Mm Um Mm Um Mm Um
Intermol-energy -3.73 -5.39 -3.81 -6.58 -6.37 -3.96 -6.08 -3.31 -8.55
Vdw-hb-disolve-
energy
-3.7 -5.33 -3.79 -6.6 -6.29 -3.95 -5.97 -3.28 -8.51
Electrostatic-
energy
-0.04 -0.06 -0.02 0.01 -0.08 0.0 -0.12 -0.03 -0.04
Total-energy 0.0 -0.17 115.77 1.01 -0.35 -0.29 0.52 -0.11 3.84
Torsional-energy 0.0 1.49 4.77 3.28 1.79 0.6 1.79 1.19 1.79
Unbound-energy 0.0 -0.17 115.77 1.01 -0.35 -0.29 0.52 -0.11 3.84
ClRMS 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
RefRMS 38.75 35.96 35.82 36.13 33.66 35.11 35.78 34.9 212.67
Rseed1 None None None None None None None None None
Rseed2 None None None None None None None None None
Active site of
protein
ARG577
TYR581
GLY574
TRP578
TRP571
GLY574
PHE575
ARG577
TRP578
PHE575
TRP578
ARG577
TYR581
TRP571
PHE575
TRP578
ARG577
TYR581
TRP571
PHE575
TRP578
ARG577
TYR581
TRP571
PHE575
TRP578
TRP571
PHE575
TRP578
TYR581
TRP571
GLY574
LYS572
TRP571
PHE575
TYR72
VAL73
TYR124
SER125
ASP74
GLY120
SEN203
TRP86
GLU202
HIS447
D. S. K. Kaladhar et al AChE and BChE studies in Alzheimers and D2M
Aging and Disease Volume 4, Number 4, August 2013 195
Table 2. Docking Results for Modelled BChE with ligands (AutoDock)
Properties Chlorp
yrifos-
oxon
1-anilino-8-
naphthalene
sulfonic acid
Dibucaine Procainamide Benzoy
lcholine
Propionyl
thicholine
Acetyl
Thio
choline
Dialkylphenyl
Phosphates
Tetra ethyl
ammonium
Binding- energy 0.27 -0.49 0.51 0.58 -5.31 0.23 -4.23 1.09 0.82
Ligand- efficiency 0.02 -0.02 0.02 0.03 -0.35 0.02 -0.42 0.08 0.09
Inhib-constant - 437.51 - - 127.78 - 794.59 - -
Inhib-constant units
- Mm - - Um - Um - -
Intermol-energy -0.32 0.49 0.21 0.28 -5.31 0.23 -4.23 -0.41 0.22
Vdw-hb-disolve-
energy
-0.32 -0.47 0.29 -0.25 -4.52 0.26 3.59 -0.4 -0.31
Electrostatic-
energy
-0.01 -0.02 0.5 0.53 -0.8 0.49 -0.64 0.0 0.53
Total-energy 0.23 0.0 0.07 -0.06 0.0 0.0 0.0 -0.49 0.11
Torsional-energy 0.6 0.0 0.3 0.3 0.0 0.0 0.0 1.49 0.6
Unbound-energy -0.23 0.0 0.07 -0.06 0.0 0.0 0.0 -0.49 -0.11
ClRMS 0.0 0.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0
RefRMS 86.69 87.98 94.47 92.5 102.11 97.06 104.0 98.24 86.94
Rseed1 None None None None None None None None None
Rseed2 None None None None None None None None None
Homology modelled structure of BChE docking was
performed with ligands using AutoDock and ligand
Benzoylcholine with energy of -5.31 kcal/mol showed
good binding affinity compared with other ligands
(Table 2).
Modelled AChE was docked with its ligands in
iGemDock and the energy values, VDW, HBond and
Electrostatic information was retrieved. Ortho-7 with
energy -83.99 kcal mol-1 has shown good docking results
(Table 3).
Table 3. Binding energies of Modelled AChE and Ligands
in kcal mol-1 using iGEMDOCK
Compound Energy VDW HBond Elec
Rivastigmine -65.5849 -58.2418 -7.34309 0
ACHE inhibitor
substrate
-49.5339 -49.5339 0 0
Ambenoniun -73.3879 -67.907 -5.48089 0
Donepezil -82.7563 -82.7563 0 0
Galanthamine -78.1548 -78.1548 0 0
HI-6 -76.1653 -64.3835 -11.7818 0
Huperzine -62.5742 -59.1771 -3.39709 0
Ortho-7 -83.9951 -77.0341 -6.96104 0
Pyridostigmine-1 -60.7988 -57.2988 -3.5 0
iGemDock is a tool used for docking using this tool,
modelled BChE protein was docked with its ligands and
results were retrieved which are shown in the Table 4
and the interaction of Dibucaine is shown in the Figure
9. Dibucaine showed better docking results with BChE
with binding energy value of -65.3 kcal mol-1 compared
with other tested compounds.
Docking was performed for modelled AChE with
nine ligands using Hex. Ortho-7 showed better docking
results with binding energy value of -3764 kcal/mol and
distance with 4 Angstroms (Table 5). Table 4. Modelled BChE and its Ligands Docking Results
in kcal mol-1 (using iGemDock)
Compound Energy VDW HBond Elec
Acetylthiocholine -35.022 -34.3761 0 -0.645895
1-anilino-8-
naphthalenesulfo
nicacid
-59.871 -43.1287 -16.7423 0
Benzoylcholine -49.1163 -44.3803 -4.14502 -0.591029
Chlorpyrifos -54.4679 -40.8784 -13.5895 0
Dialkylphenylph
osphates
-50.2987 -35.1747 -15.124 0
Dibucaine -65.3374 -58.3615 -6.97593 0
Procainamide -48.351 -42.5862 -5.76476 0
Tetraethylammo
nium
-28.2795 -28.2795 0 0
Propionylthiocho
line
-41.4 -31.13 -10.3 0.03
Modelled BChE was docked with its ligand using
the tool Hex. The energy values and R-values are
retrieved and shown in Table 6. An energy value of -
270.93 kcal mol-1 for Dibucaine showed good docking
result with modelled BChE.
DISCUSSION
The functional properties of proteins are determined by
their three-dimensional structures, self assemble into
advanced structures is chargeable for their dominant role
in biological functions. The range of life within the
contemporary world has been generated by evolutionary
processes functioning on these core processes through
millions years. The generation of this diversity has fairly
often resulted from the difference of existing
D. S. K. Kaladhar et al AChE and BChE studies in Alzheimers and D2M
Aging and Disease Volume 4, Number 4, August 2013 196
biochemical components to new biological components
instead of the event of essentially new biochemical
technology [38, 39]. BChE deficient individuals are
typically healthy with no apparent signs of diseases [40].
Figure 9: Docking results
There is lot of evidence that supports cholinergic
mechanisms modulate learning and memory formation
[41, 42]. The strength and influence of any neural system
on behavioral output is modulated by internal secretion
standing by selective lesions of hippocampus, striatum,
and also the amygdaloid nucleus [43]. AChE and BChE
contains multiple potential substrate binding areas, is
responsible for caparison and delivery of Benzoylcholine
to the active site [44, 45]. Individuals with regular BChE
and AChE have a high intravenous anesthetic range [46].
Obidoxime, trimedoxime, pralidoxime (2-PAM) and
asoxime (HI-6) are commercial drugs containing the
oxime group are able to split organophoshorus moiety
from the the active site resulting in liberation and
enzyme reactivation. All the chosen molecules have
shown negative energies and therefore will target in
control the AChE and BChE levels in humans.
Rivastigmine and donepezil controls brain acetylcholine
levels has shown by experimentation by Naik et al., in
2009 in acetylcholinesterase-deficient mice [47]. Huperzine and AChE inhibitor substrates from
Huperzia cf chamaeleon and Huperzia reflexa, Lycopodium clavatum subsp. Clavatum showed
Table 5. Docking Result for Modelled AChE and its
Ligand in kcal mol-1 (using Hex)
LIGAND Etotal in kcal mol(-1) R-Value In A
Donepezil -235.98 17.6
Galanthamine -235.98 17.6
HI-6 -229.82 19.2
Rivastigmine -185.69 12.0
Huperzine -166.63 7.2
Ortho-7 -3764.00 4.0
Pyridostigmine -153.42 6.4
Ambenoniun -247.22 8.0
AChE
inhibitor
substrate
-137.30 7.2
D. S. K. Kaladhar et al AChE and BChE studies in Alzheimers and D2M
Aging and Disease Volume 4, Number 4, August 2013 197
strong AChE inhibition [48, 49]. Galanthamine, an
alkaloid derivative phytocompound isolated from
snowdrop (Galanthus nivalis L.) [50] and Huperzine A,
a naturally occurring sesquiterpene alkaloid compound
isolated from Huperzia serrata (Thunb.) Trev., [50, 51]
are the latest anticholinesterase drugs using against AD.
Plant derived alkaloids like galanthamine, huperzine A
and rivastigmine are known for their AChE inhibitory
activity [52, 53]. Ambenonium, an old AChE inhibitor
[54, 55], Ortho-7, a more efficient reactivator than HI-6
[56], Donepezil [57] and Pyridostigmine [56] has shown
good activity against AChE. The present report has also
been proved good with high binding affinity of AChE
with Ortho-7.
Table 6. Docking Results for modelled BChE and its
Ligand in kcal mol-1 (using Hex)
LIGANDS Etotal
in kcal mol(-1)
R-value
In A
Chlorpyrifos-oxon -186.55 21.6
1-analino-8-naphtalene sulfonic acid -192.87 21.6
Dibucaine -270.93 20.0
Procainamide -214.37 20.0
Benzoylcholine -208.92 18.4
Propionyl thiocholine -172.31 16.8
Acetylthiocholine -154.31 12.0
Di alkyl phenyl phosphates -174.23 21.6
Tetra ethyl ammonium -142.29 17.6
People with BChE deficiency are likely to be
intolerant of standard doses of the anti-Alzheimer's drugs
such as huperzine A and donepezil [58]. Chlorpyrifos
oxon [59], 1-anilino-8-naphthalene sulfonic acid [60],
Dibucaine, Procainamide, Benzoylcholine, Propionyl
thicholine, Acetyl thiocholine, Dialkylphenylphosphates,
Tetra ethyl ammonium are virtually screened and
selected for the activity against BChE [61. 62]. The
present report has also been proved good with high
binding affinity of BChE with Dibucaine as drug to AD
and D2M.
BChE, resembling AChE, is typically associated
with catalyzing the hydrolysis of the neurotransmitter
acetylcholine (ACh) and yield choline and acetic acid.
BChE has a clear role in neural functions in the co-
regulation of cholinergic and non-cholinergic
neurotransmission [63]. Cerebrovascular disease is
thought to decrease the threshold at which amyloid
deposition causes the manifestations of AD that starts
with memory impairment, reaching the threshold of mild
cognitive impairment, and eventually dementia [64].
Protein interactions between AChE and BChE with
other proteins were retrieved using STRING, HPRD and
Pathway linker database. Protein-Protein interactions in
molecular disorders have been already studied using
STRING and HPRD in MAPK pathway [65]. The
AChE and BChE proteins [66, 67, 68] showed
interaction with few other proteins like COLQ, NGF etc.
The phosphomotifs for the protein AChE and BChE
were also be retrieved and studied for better
understanding of relationships in homologous sequences.
AChE and BChE are regular targets of a large
number of toxins and understanding of cholinesterase
structure and the biological mechanisms of inhibition is
necessary for novel drug development. Dibucaine,
Ortho-7 and HI-6 are predicted as good targets for AChE
and BChE proteins and can control metabolic syndromes
in humans.
The work concludes hat Cholinesterases play an
important role in the human system. Humans in the
present generation are exposing toxic products in body,
in the form of pesticides and microbial toxins in foods.
AchE and BChE are the proteins involved in ageing
disease like Alzheimers and D2M. The present study shows the functional studies using phylogeny and protein
interactions. The virtual molecular screening of drugs on
AChE and BChE has been studied using docking
methods.
Acknowledgements
Author would like to thank management and staff of
GITAM University Visakhapatnam, India for their kind
support in bringing out the above literature and
providing lab facilities.
Conflict of interest
The authors do not have any conflict(s) of interest
References
[1] Quinn DM (1987). Acetylcholinesterase: enzyme
structure, reaction dynamics, and virtual transition
states. Chemical Review, 87: 955979 [2] Taylor P and Radic Z (1994). The cholinesterases:from
genes to proteins. Annual Review of Pharmacology and
Toxicology, 34: 281320 [3] Massoulie J, Pezzementi L, Bon S, Krejci E and
Vallette FM (1993). Molecular and cellular biology of
cholinesterases. Progress in Neurobiology, 41 (1): 3191
[4] Chacho LW and Cerf JA (1960). Histochemical
localization of cholinesterase in the amphibian spinal
cord and alterations following ventral root
section. Journal of Anatomy, 94: 7481 [5] Koelle GB (1984). The histochemical localization of
cholinesterases in the central nervous system of the
rat. Journal of Comparative Anatomy, 100 (1): 211235
D. S. K. Kaladhar et al AChE and BChE studies in Alzheimers and D2M
Aging and Disease Volume 4, Number 4, August 2013 198
[6] McClintock TS (1989). AChE BW. Histamine directly
gates a chloride channel in lobster olfactory receptor
neurons. PNAS, 86: 81378141 [7] Nee okura A (2003). Butyrylcholiesterase structure
and physiological importance. Turk j.biochem, 28(2):
5461 [8] Paul HA (1994). Structure and dynamics of the active
site gorge of acetylcholinesterase: synergistic use of
molecular dynamic, simulation and x-ray
crystallography. Protein sciences, 3: 188197 [9] Mohammad S and Syed IR (1989). Erythrocyte
membrane acetylcholiesterase in type1 (insulin
dependent) Diabetes Milletus. Biochem J, 259: 897899
[10] Allam A (2008). Bioinformatic anaylsis of Alzheimers disease and type 2 Diabetes Milletus. A Bioinformatic
Approach, 13: 050054 [11] Ekholm M (2001). Predicting relative binding free
energies as substrate and inhibitors of acetyland
butyrylcholinesterase. Theo Chem, 572: 2534 [12] Nachmansohn D and Wilson IB (1951). The enzymatic
hydrolysis and synthesis of acetylcholine. Adv Enzymol
Relat Subj Biochem, 12: 259339 [13] Tougu V (2001). Acetylcholinesterase: Mechanism of
catalysis and inhibition. Curr Med Chem, 1: 155170 [14] Dave KR, Syal AR and Katyare SS (2000). Tissue
cholinesterases: A comparative study of their kinetic
properties. Z. Naturforsch, 55c: 100108 [15] Biessels GJ and Kappalle LJ (2005). Increased risk of
Alzheimers diease in type II diabetes : Insulin resistance of the brain or insulin induced amyloid
pathology. Biochem sac trans, 33: 10411044 [16] Nigel HG (2005). Selective BChE inhibition elevates
brain acetlcholine, aguments leaning and lowers
Alzheimers -amyloid peptide in rodent. Biochem sac trans, 102: 1721317218
[17] Tabet N (2006). Acetylcholinesterase inhibitors for
Alzheimers disease: anti-inflammatories in acetylcholine clotting. Age and ageing, 35: 336338
[18] Massouli J, Pezzementi L, Bon S, Krejci E and Valette
FM (1992). Molecular and cellular biology of
cholinesterases. Neurobiology, 41: 3191 [19] Around C and Oksana L (1989). Comparison of
butyrylcholinesterase and AChEtylcholinesterase.
Biochem J, 260: 625634 [20] Tama E (2007). Plant-derived human
acetylcholinesterase-R provides protection from lethal
organophosphate poisoning and its chronic after math.
FasebJ, 21: 29612969 [21] He L, Lawrence MS, Florian N, Marie-Thrse F,
Patrick M and Oksana L (2007). Aging pathways for
organophosphate-inhibited human butyrylcholinesterase
including novel pathways for isomalathion resolved by
mass spectrometry. Toxicology science, 100(1): 136145
[22] Ryhnen RJJ (1983). Pseudocholinesterase activity in
some human body fluids. Gen Pharmacol, 14: 459460 [23] Baumgartner RN, Heymsfield SB and Roche AF
(2004). Human body composition and the epidemiology
of chronic disease. Obes Res, 199: 7395
[24] Andras S (2005). Prediction of physical protein-protein
interactions. Phys biology, s1-s16: 10881478 [25] Eric MP and Stanley F (1995). Protein-Protein
Interactions: Methods for Detection and Analysis.
Microbiological reviews, 59(1): 94123 [26] Damain S (2011). The STRING database in 2011:
functional interaction networks of proteins globally
integrated and scored. Nucleic acids research, 39: 561568
[27] Illes JF (2010). Network based tools for the
identification of novel drug targets. Computational
biology, 4: 173185 [28] Gopa RM, Suresh M, Kumaran K, Kannabiran N,
Suresh S, Bala P, et al. (2006). Human protein
reference database--2006 update. Nucleic acids
research, 34: 411414 [29] Dowluru SVGKK, Potladurthi CS, Padmanabhuni
VNR, Amajala KC, Duddukuri GR, Vadlapudi VR,
Erva RR, Sudabattula VK and Divyakolu VK (2012)
Towards an understating of signal transduction protein
interaction networks. Bioinformation, 8(9):437439 [30] Valle AM, Radic Z, Rana BK, Mahboubi V, Wessel J,
Shih PA, Rao F, O'Connor DT and Taylor P (2011).
Naturally occurring variations in the human
cholinesterase genes: heritability and association with
cardiovascular and metabolic traits. J Pharmacol Exp
Ther, 338(1):125133 [31] Shenhar-Tsarfaty S, Bruck T, Bennett ER, Bravman T,
Aassayag EB, Waiskopf N, Rogowski O, Bornstein N,
Berliner S and Soreq H (2011). Butyrylcholinesterase
interactions with amylin may protect pancreatic cells in
metabolic syndrome. Journal of Cellular and Molecular
Medicine, 15(8):17471756 [32] Siskov K, Bilka F, Adameov A, Balazov A, Mydla
M and Paulikov I (2012). Influence of lipid imbalance
on butyrylcholinesterase activity and biotransformation
efficiency. Pharmazie, 67(4): 345350 [33] Rao AA, Jyothsna G, Shalini P, Kumar A, Bhattacharya
A and Kashyap A (2012) Exploring the role of BCHE
in the onset of Diabetes, Obesity and Neurological
Disorders. Bioinformation, 8(6): 276280 [34] Giacobini E (2004). Cholinesterase inhibitors: new
roles and therapeutic alternatives. Pharmacol Res,
50(4): 433440 [35] Pepeu G and Giovannini MG (2009). Cholinesterase
inhibitors and memory. Chem-Biol Interact, 187: 403408
[36] Hartmann J, Kiewert C, Duysen EG, Lockridge O,
Greig NH and Jochen K (2007). Excessive hippocampal
acetylcholine levels in acetylcholinesterase-deficient
mice are moderated by butyrylcholinesterase activity. J
Neurochem, 100: 14211429 [37] Kaladhar DSVGK, Anusha N, Varahala RV, Surekha C
and Sudhakar M (2012). Regulation of Metabolic
Syndromes by means of controlling diseased Ache and
Bche with Multitarget Inhibitors through in silico
techniques. Journal of Computational Methods in
Molecular Design, 2(4): 122129.
D. S. K. Kaladhar et al AChE and BChE studies in Alzheimers and D2M
Aging and Disease Volume 4, Number 4, August 2013 199
[38] Jere DH and Gail GH (1977). Nutritional Anthropology
and Biological Adaptation. Annual Review of
Anthropology, 6: 69101 [39] Hengeveld R (2005). The Wonderful Crucible of Life's
Creation: An Essay on Contingency versus Inevitability
of Phylogenetic Development. Current themes in
theoretical biology (Springer Netherlands), 129157. [40] Manoharan I, Boopathy R, Darvesh S and Lockridge O
(2007). A medial health report on individuals with
silent butyrylcholinesterase in Vysya community of
India. Clin Chim Acta, 378: 128135 [41] Gold PE (2003). Acetylcholine modulation of neural
systems involved in learning and memory. Neurobiol
Learn Mem, 80(3): 194210 [42] McIntyre CK, Pal SN, Marriott LK and Gold PE
(2002). Competition between memory systems:
acetylcholine release in the hippocampus correlates
negatively with good performance on an amygdala-
dependent task. J Neurosci, 22(3): 11711176 [43] Mizumori SJ, Yeshenko O, Gill KM and Davis DM
(2004). Parallel processing across neural systems:
implications for a multiple memory system hypothesis.
Neurobiol Learn Mem, 82(3): 27898 [44] Tougu V (2001). Acetylcholinesterase: Mechanism of
Catalysis and Inhibition. Current Medicinal Chemistry -
Central Nervous System Agents, 1(2): 155170 [45] Ines P, Tomica H, Sranka T and Zlatko M (2002).
Interactions of chiral quinuclidin-3-yl benzoates with
butyrylcholinesterase: kinetic study and docking
simulations. Journal of Physical Organic Chemistry.
Special Issue: Organic Reactivity, 15(8): 608614 [46] Miroslav P (2011) Cholinesterases, A target of
pharmacology and toxicology. Biomed Pap Med Fac
Univ Palacky Olomouc Czech Repub, 155(3): 219230 [47] Naik RS, Hartmann J, Kiewert C, Duysen EG and
Lockridge O (2009). Effects of rivastigmine and
donepezil on brian acetylcholine levels in
acetylcholinesterase-deficient mice. J Pharm
Pharmaceut Sci, 12: 7985 [48] Caldern AI, Simithy-Williams J, Sanchez R, Espinosa
A Valdespino I and Gupta MP (2013). Lycopodiaceae
from Panama: A new source of acetylcholinesterase
inhibitors. Nat Prod Res, 27(4-5): 500-505
[49] Yang L, Ye CY, Huang XT, Tang XC and Zhang HY
(2012). Decreased Accumulation of Subcellular
Amyloid- with Improved Mitochondrial Function Mediates the Neuroprotective Effect of Huperzine A. J
Alzheimers Dis, 31(1): 131142 [50] Orhan IE, Orhan G and Gurkas E (2011). An overview
on natural cholinesterase inhibitors--a multi-targeted
drug class and their mass production. Mini Rev Med
Chem, 11(10): 836842 [51] Wang Y, Zeng QG, Zhang ZB, Yan RM and Wang LY
(2011). Isolation and characterization of endophytic
huperzine A-producing fungi from Huperzia serrata. J
Ind Microbiol Biotechnol, 38(9): 12671278 [52] Yang ZD, Duan DZ, Xue WW, Yao XJ and Li S
(2012). Steroidal alkaloids from Holarrhena
antidysenterica as acetylcholinesterase inhibitors and
the investigation for structure-activity relationships.
Life Sci, 90(23-24): 929933 [53] Isik AT, Bozoglu E and Eker D (2012). AChE and
BuChE inhibition by rivastigmin have no effect on
peripheral insulin resistance in elderly patients with
Alzheimer disease. J Nutr Health Aging, 16(2): 139141
[54] Komloova M, Musilek K, Horova A, Holas O and
Dohnal V (2011). Preparation, in vitro screening and
molecular modelling of symmetrical bis-quinolinium
cholinesterase inhibitors--implications for early
myasthenia gravis treatment. Bioorg Med Chem Lett,
21(8): 25052509 [55] Bolognesi ML, Cavalli A, Andrisano V, Bartolini M
and Banzi R (2003). Design, synthesis and biological
evaluation of ambenonium derivatives as AChE
inhibitors. Farmaco, 58(9): 917928 [56] Kesharwani MK, Ganguly B, Das A and
Bandyopadhyay T (2010). Differential binding of
bispyridinium oxime drugs with acetylcholinesterase.
Acta Pharmacol Sin, 31(3): 313328 [57] Pohanka M (2012). Acetylcholinesterase inhibitors: a
patent review (2008 - present). Expert Opin Ther Pat,
22(8): 871886 [58] Duysen EG, Li B, Darvesh S and Lockridge O (2007).
Sensitivity of butyrylcholinesterase knockout mice to (-
-)-huperzine A and donepezil suggests humans with
butyrylcholinesterase deficiency may not tolerate these
Alzheimer's disease drugs and indicates
butyrylcholinesterase function in neurotransmission.
Toxicology, 233(1-3): 6069 [59] Amitai G, Moorad D, Adani R and Doctor BP (1998).
Inhibition of acetylcholinesterase and
butyrylcholinesterase by chlorpyrifos-oxon. Biochem
Pharmacol, 56(3): 293299 [60] Christian ST and Janetzko RA (1971). Comparative
study of the interactions of the nonpolar fluorescent
ligand, 1-anilino-8-naphthalene sulfonic acid, with
butyryl and acetylcholinesterase. Archives of
Biochemistry and Biophysics, 145(1):169178 [61] Brazzolotto X, Wandhammer M, Ronco C, Trovaslet
M, Jean L, Lockridge O, Renard PY and Nachon F
(2012). Human butyrylcholinesterase produced in insect
cells: huprine-based affinity purification and crystal
structure. FEBS J, 279(16): 29052916 [62] Johnson G and Moore SW (2000). Cholinesterase-like
catalytic antibodies: reaction with substrates and
inhibitors. Mol Immunol, 37(12-13): 707719 [63] Hay D, Israel S, Michal H, Terrone LR and Joel LS
(2010). Acetylcholinesterase from 3D structure to
function. Chem Biol Interect, 187(1-3): 1022 [64] Terry AV and Buccafusco JJ (2003). The cholinergic
hypothesis of Age and Alzheimers diseaserelated cognitive deficits: recent challenges and their
implications for novel drug development. J Pharmacol
Exp Ther, 306: 821827 [65] Kaladhar SD, Potladurthi CS, Padmanabhuni VNR,
Amajala KC, Duddukuri GR, Vadlapudi VR,
Potladurthi S, Erva RR, Sudabattula VK, Divyakolu
VK, Gajjala BR (2013). Protein Interaction Networks in
D. S. K. Kaladhar et al AChE and BChE studies in Alzheimers and D2M
Aging and Disease Volume 4, Number 4, August 2013 200
Metallo Proteins and Docking Approaches of Metallic
Compounds with TIMP and MMP in Control of MAPK
Pathway. Letters in Drug Design & Discovery, 10(1):
4955 [66] Kaladhar DSVGK, Pruthvitej C, Nageswara RPV,
Satya SVB. (2009). An in silico environment for
sequence-structure-function analysis and developing
drug targets on alzheimer and parkinson diseases.
International Journal of Computational intelligence and
Bioinformatics, 1(2): 7580
[67] Kaladhar DSVGK, Nageswara RPV and Rachel KV
(2009). Designing specific inhibitors for the (Tau-P)n
protein in Alzheimers disease. International Journal of Bioinformatics, 2(2): 6972
[68] Sridhar GR, Rao AA, Srinivas K, Nirmala G, Lakshmi
G, Suryanarayna D, Rao PV, Kaladhar DG, Kumar SV,
Devi TU, Nitesh T and Hanuman T (2010).
Butyrylcholinesterase in metabolic syndrome. Medical
Hypotheses, 75: 648651