Does arsenate inhibit glyceraldehyde 3-phosphate dehydrogenase?

[scilearner]

I know it resembles a phosphate. Did a search it was very vague. Thanks

[hypervalent_iodine]

I don't know about this enzyme specifically, but arsenates can mimic phosphates in a lot of cases - and they do a good job of it too. Interestingly, a somewhat recent study in America found a species of bacteria that can substitute arsenic in place of phosphate and maintain themselves reasonably well. There was a thread on that study some time ago in the Science News section. Do you have access to a university library site or access to a scientific journal search engine? If so, you might find it quite helpful. If not, you should try using Google scholar or try finding a biochemistry text book.

[Horza2002]

From what I understand, then no it won't inhibit the enzyme. What it will most likely do, as hypervalent has said, is take the place of phosphate and incorportate itself into the product.

 

The catalytic mechanism for the desired transformation requires the use of a cystein residue in the active site. The exposed thiol of the cystein is what tethers the starting material to the active site aswell as catalysing the reactions. As a result, inhibitors of this enzyme will be ones that infere with this thiol group. Oxidsers (that convert the thiol to a sulphoxide or sulphone) or heavy metals (palladium, gold, lead) will inhibit this enzyme; heavy metals are very thiophilic.

[hypervalent_iodine]

From what I understand, then no it won't inhibit the enzyme. What it will most likely do, as hypervalent has said, is take the place of phosphate and incorportate itself into the product.

 

The catalytic mechanism for the desired transformation requires the use of a cystein residue in the active site. The exposed thiol of the cystein is what tethers the starting material to the active site aswell as catalysing the reactions. As a result, inhibitors of this enzyme will be ones that infere with this thiol group. Oxidsers (that convert the thiol to a sulphoxide or sulphone) or heavy metals (palladium, gold, lead) will inhibit this enzyme; heavy metals are very thiophilic.

 

From what I've read, there are actually a few metabolic processes where substituting arsenic in place of phosphorous does result in the irreversible inhibition of certain enzymes. Off the top of my head I couldn't tell you which enzymes, but I do recall reading it when I was looking into that article I mentioned in my above post (the one about bacteria).