title: Purification and properties of soman-hydrolyzing enzyme from human liver.
abstract: A soman-hydrolyzing enzyme (somanase) was purified from human liver. The human somanase is capable of hydrolyzing pinacolyl methylphosphonofluoridate (soman), diisopropylphosphorofluoridate (DFP), and ethyl-N-dimethyl phosphoramidocyanidate (Tabun) with P-F or P-CN bonding, but not ethyl (S-2-diisopropylaminoethyl) methylphosphonothiolate (VX) and diethyl-p-nitro-phosphenylphosphate (paraoxon) with P-S or P-O bonding. The somanase has been purified 1570-fold with a specific activity of 41.4 mumol/min/mg protein. Its molecular weight is around 58 kDa determined by SDS-PAGE. The somanase could be stimulated by the divalent cations Mn+2, Mg+2, and Co+2, where CO+2 activation is the highest. The requirement of disulfide bonds for the enzyme activity was demonstrated by the inhibition effect of DTT.
authors.affiliation: Institute of Pharmacology and Toxicology, Beijing, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Wang
authors.forename: M
authors.initials: M
authors.lastname: Sun
authors.forename: H
authors.initials: H
authors.lastname: Zhang
authors.forename: C
authors.initials: C
authors.lastname: Huang
mesh_terms: D002384:Catalysis; D004950:Esterases / Q000737:chemistry / Q000302:isolation & purification*; D006801:Humans; D006868:Hydrolysis; D008099:Liver / Q000201:enzymology*; D008970:Molecular Weight; D044345:Phosphoric Triester Hydrolases
chemical_list: D004950:Esterases; D044345:Phosphoric Triester Hydrolases; C020061:diisopropyl-fluorophosphatase