Accession Number:

ADA272240

Title:

Stereoselectivity of Soman Detoxication by Organophosphorus Acid Anhydrases from Escherichia coli

Descriptive Note:

Journal article,

Corporate Author:

ARMY NATICK RESEARCH DEVELOPMENT AND ENGINEERING CENTER MA

Report Date:

1993-01-01

Pagination or Media Count:

11.0

Abstract:

Three organophosphorus acid anhydrases have been isolated from E. coli by gel filtration and ion exchange column procedures, and further identified by gel electrophoresis. All three have molecular weights in the 120 000 - 140 000 range. Two of the-Tn hydrolyze racemic 1,2,2- trimethylpropylmethylphosphonofluoridate soman to completion at a single rate and, in parallel with this, detoxify soman at a comparable rate. The third enzyme appears to show stereoselectivity with respect to the two pairs of isomers of soman in that it hydrolyzes the racemic mixture at a fast and a slow rate, the latter approaching the nonenzymatic rate, and detoxifies soman only at a slower rate. In the past, organophosphorus acid anhydrases from bacterial and mammalian sources have been assayed either as crude sonicates or homogenates, or as cold ethanol precipitated fractions. Major discrepancies among laboratories have probably been due either to the assay of mixtures of varying proportions of these three enzymes depending on the various organs or organisms used as the source, or to the purification of one of the enzymes at the expense of the others. For E. coli, a fourth organophosphorus acid anhydrase is also present but at a considerably lower activity. Detoxification, DFPase, OPA Anhydrase, Soman, Stereoisomers-1-2-2-Trimethylpropylmethylphosphonofluoridate

Subject Categories:

  • Microbiology
  • Organic Chemistry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE