A Physiological and Biochemical Basis for the Action of Soman and Related Agents at the Acetylcholine Receptor

摘要

An enzyme that detoxifies DFP and Soman (squid type DFPase) has been covalently linked to agarose resin. A column of this enzyme will detoxify a solution of Soman passed through it. The squid type DFPase is a different enzyme from the mammalian DFPase (kidney). The former has a 26,600 mol. wt., is very stable, is not stimulated or is even slightly inhibited by Mn(++), and hydrolyzes DFP faster than Soman (although it does hydrolyze and thus detoxify the AChE-inhibiting diastereoisomer(s) of Soman). The mammalian enzyme has a 60,000 mol. wt., is unstable, is markedly stimulated by Mn(++), and hydrolyzes Soman faster than DFP. DFPase is also found in squid salivary gland, but is not equatable with the squid salivary gland toxin. The squid salivary gland toxin is also not TTX (as it is in octopus salivary gland). This finding of DFPase in the squid salivary gland suggests a naturally occurring toxic agent in the marine environment equivalent to the toxic organophosphorous compounds. It is also noteworthy that the squid salivary gland toxin is a protein. VX has also been tested as a substrate for the squid type DFPase, but the VX is not detoxified by this enzyme. (Author)