Sarin - Biological Effects

Biological Effects

Its mechanism of action resembles that of some commonly used insecticides, such as malathion. In terms of biological activity, it resembles carbamate insecticides such as Sevin and medicines pyridostigmine, neostigmine, and physostigmine. Like other nerve agents, sarin attacks the nervous system.

Specifically, sarin is a potent inhibitor of the enzyme cholinesterase. Sarin acts on cholinesterase by forming a covalent bond with the particular serine residue at the active site. Fluoride is the leaving group, and the resulting phosphoester is robust but biologically inactive. With the enzyme inhibited, acetylcholine builds up in the synapse and continues to act so that any nerve impulses are, in effect, continually transmitted. Normally, the acetylcholinesterase breaks down the acetylcholine in the synaptic cleft in order to allow the effector muscle or organ to relax.