Post on 21-Dec-2015
transcript
Hadean Archean Proterozoic
Mesozoic
Cenozo
ic
Paleozoic
inthe beginning…
Nov. 9 2005
today1 bya2 bya3 bya4 bya
3.5 bya!
Oldest fossils: stromatolites = Calcium carbonate deposits from blue-green algae or cyanobacteria.
0.5 bya
N2 + 3 H2 --> 2 NH3
BANG!
Hadean4.5 -3.8 bya
Archean3.8 -2.5 bya
Oldest rocks?
Most famous characteristic?Nitrogen “fixing” bacteria:
4.5 bya!
What do we find deep withincyanobacteria’samazing N2-fixing machinery?
MoMolybdenum
(Greek ‘molybdos’ ) lead-like
“Moly”
# 42
The Answer to Life, the Universe, and Everything (?)
540 mya
Mesozoic2.5 -0.6 mya
Global catastrophe!
Cenozoic65 mya - today!
“age of mammals”
“age of dinosaurs”
quagga
Paleozoic540 - 250 mya
250 mya 65 mya
Plants!!
Animals!!Anotherextinction!!
Has evolution moved on without #42 - Mo?
Grown without MoGrown with Mo
Tobacco plants (Arabidopsis thaliana)
Healthy(wild type)
Sick(mutant)
All plants requirethe molybdoenzymeNitrate Reductase
nitrate nitrite
Nitrate
Nitrite
Proteins
inthe Beginningof Life…
1 bya2 bya3 bya4 bya
CyanobacteriaNeed
Mo
PlantsNeed
Mo
What about the animals?
sulfite oxidase
xanthine oxidase
enzyme in mammalian milk
Got Mo?
aldehyde oxidase
two enzymes in liversof mammals and avians
Why the correct oxidation state matters
MRI of brain of deceased babywith Sulfite Oxidase Deficiency MRI of healthy brain
The baby died because this reaction didn’t happen:
SO32- + H2O ---> SO4
2- + 2H+ + 2e- Sulfite SulfateS4+ S6+
The baby has a genetic defect in the enzyme that catalyzes this reaction.Babies with this genetic disease die within hours.The enzyme is Sulfite Oxidase.
You have it in your liver.
Oxidation SO32- + H2O ---> SO4
2- + 2H+ + 2e- half reaction S4+ in Sulfite S6+ in Sulfate
Reduction Mo6+ + 2e- ---> Mo4+ half reaction
Net redox reactionSO3
2- + H2O + Mo6+ ---> SO42- + 2H+ + Mo4+
Review the terms:
aldehyde oxidase sulfite oxidasexanthine dehydrogenase
Human Molybdenum Cofactor Disorder: Combined Oxidase Deficiency
sulfite sulfate
•Mental/motor retardation•Epileptic seizures•Brain atrophy•Dislocated ocular lens•death
xanthine uric acid
•xanthinuria•(gout)
hypoxanthine xanthine
•No detoxification of heterocycles
+ Mo
defective molybdoenzymes
Human Molybdoenzyme Deficiencies: Cured with more Mo?
Not repaired by adding Mo alone
Non-functional enzyme
Bioinorganic Chemistry
1. Not having the structure or organization of living bodies2. Not characterized by vital processes3. Not fundamental or related; extraneous 4. Pertaining to compounds that are not hydrocarbons5. Mineral
1. (Gr. “bios” ‘life, course or way of living’). In compounds formed in Greek itself, as biography; and in modernscientific words in which bio- is extended to mean ‘organic life.’
2. A prefix meaning “life” Websters, OED
Bioinorganic ChemistryMolybdenum Enzymes Hemoglobin (Fe)
Manganese Enzymes
Zinc Enzymes (Zn)
Auranofin (Au) arthritisCis-platin (Pt) cancer
Copper Enzymes (Cu)Vitamin B12 (Co) Iron enzymes
Tungsten Enzymes
Therapeutics
V, Ti, Cr
Bioinorganic ChemistryMolybdenum Enzymes Hemoglobin (Fe)
Manganese Enzymes
Zinc Enzymes (Zn)
Aurial (Au) arthritisCis-platin (Pt) cancer
Copper Enzymes (Cu)Vitamin B12 (Co) Iron enzymes
Tungsten Enzymes
Therapeutic s
V, Ti, Cr
Questions asked of molybdoenzymes and their model compounds:
-What is the redox potential ( energy of) Mo redox reactions?
- What are the structural details? What is bond order? (angles, bond distances)
-How well do models mimic reactions of Mo in enzymes? in structure in reactivity
Mo Chemistry1.Oxidation states
Mo occurs in oxidation states from 0 +6Project 1 will generate complexes in states +4 –
6, same as enzymes
Mo Chemistry2. Geometries: Mo complexes have Coordination Numbers
from CN 4 8 Project 1 uses reagents or makes products
with CN 4 7
3. Reaction Chemistry Mo S; dtc ligand
Mo O; Mo=O ligands
Mo Chemistry
What do you get if you multiply nine by six?
Molybdenum, atomic # 42: is it the answer to Life, the Universe and Everything?
What’s the Ultimate Question?
Adams speculates in “The Restaurant at the End of the Universe”:
Sure looks like it!
O
Mo+6
OS
S
O
MoOS
S
O
Mo+4
S
S
O
Mo+4OS
S
SO
OO
OSO
OO
O
Mo+4
S
SH
H
O
Mo+5OHS
S
a
- H+, - e -
- H+, - e -
+ SO32-
- SO42-
+ H2O
oxygen
atom
transfer
coupled
proton
electron
transfer
A proposed catalytic cycle for how Mo oxidizes SO32-
Mo
molybdopterinpterin
dithiolene
Mo
Ball and stick diagram Chemical structure diagram
S
S
O
HN NH
HNNO
O
NH2
MoO NN
NH2
O
HO
P OP O
O
O
OO
OH
S
S
O
HN NH
HNNO
O
NH2
MoO NN
NH2
O
HO
P OP O
O
O
OO
OH
S
S
O
HN NH
HNNO
O
NH2
MoO NN
NH2
O
HO
P OP O
O
O
OO
OH
Protein structuredestroyed
Mo compoundreleased (isolated)
rapid decomposition
HS
SH
HO
HN
NH
HN
N
O
O
H2N
Mo
P
O
O
O
N
N
HN
N
O
H2N S
S
CHOHCH2OH