another example: carbonic anhydrase. zn active site in -carbonic anhydrase
TRANSCRIPT
another example:
Carbonic Anhydrase
Zn
Zn
Active site in -carbonic anhydrase
Active site and mechanism in -carbonic anhydrase
deprotonation
Nucleophilicattack on CO2
Charge stabilization
START
:B(GLU)H+:B(GLU)
CO2 --> [CO3]2-
CO2 --> glucoseCO2 <-- [CO3]2-
glucose --> CO2
Carbonic Anhydraseis critically important in global C- cycle
CO2 --> [CO3]2-
CO2 <-- [CO3]2-
Carbonic Anhydraseimportant in global C- cycle because catalyzes both directions!
Phytoplankton do this:HCO3
- CO2
Diatoms do this:CO2 HCO3
-
CA importance means these critters are growth limited:when there’s too little Zn, can use Cd and Co!!
Acid/base chemisty in catalysis of Mo enzymes: oxidation of SO32-
See in this step how
Mo charge affects H2O
acidity
ditto