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nismaratwork
#7
Mar16-11, 01:21 AM
P: 2,284
Quote Quote by epenguin View Post
I think that blocks cytochromes, though I think before that you are killed by its blocking haemoglobin, which is often called an 'honorary enzyme' anyway. What does work by blocking cytochromes is cyanide.

Then everyone should have some awareness of the organophosphorus compounds, some the notorious nerve gases, others insecticides, which act by reacting covalently with acetyl cholinesterase so blocking transmission of nervous impulses. Curare on the other hand is a a blocker of acetylcholine receptors - and surprisingly in view of the previous an antidote such as physostigmine is also an acetylcholinesterase inhibitor - which works by letting acetylcholine build up to overcome the curare, but unlike the organophoshates is bound reversibly.http://en.wikipedia.org/wiki/Physostigmine OK the receptor is a protein controlling an ion gate, but between such physical-chemical and strictly chemical actions you find yourself not making distinction when you get into such areas.

I do not remember an example but some toxic substances not toxic as such but are transformed enzymatically into other substances that are. And then there are lots of enzymes that do the opposite and detoxify substances, oxidise them, methylate them, and I don't remember what else. Quite a big and practical area.

Here is another enzyme with complicated action like those mentioned by Jon http://www.ebi.ac.uk/interpro/potm/2005_9/Page2.htm
Hmmmm, Aflatoxin is reduced, but at high doses that metabolysis can cause an acute and fatal reaction?

If not for the "inorganic" stipulation, I'd agree with everything you listed.

Ohhh, Syndney Funnel Web venom contains a truly wicked acetylcholinesterase inhibitor... ugly way to go.

edit: Phosgene, if you don't choke on it, I believe becomes quite toxis during lysis... I could be wrong... will check tomorrow.