Phosphorus-containing enzymes dependence

The phosphorus-containing nerve gases constitute the most deadly poisons at present known to man. Nerve gases are compounds which block nervous activity and cause death, either extremely quickly or agonisingly and very slowly, depending on the conditions of exposure. They act by inhibiting the action of cholinesterase, the enzyme which controls the hydrolysis of acetylcholine, the substance immediately involved in the conduction and transmission of nerve impulses in the body. This inhibition is associated with a process of phosphorylation whereby the toxic compound becomes linked to the enzyme by a P-O-C linkage. 

---