Premium
Oxidative biodegradation of phosphorothiolates by fungal laccase
Author(s) -
Amitai G,
Adani R,
Sod-Moriah G,
Rabinovitz I,
Vincze A,
Leader H,
Chefetz B,
Leibovitz-Persky L,
Friesem D,
Hadar Y
Publication year - 1998
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(98)01300-3
Subject(s) - laccase , abts , chemistry , biodegradation , hydrolysis , chromatography , enzymatic hydrolysis , organic chemistry , nuclear chemistry , enzyme , dpph , antioxidant
Organophosphorus (OP) insecticides and nerve agents that contain P‐S bond are relatively more resistant to enzymatic hydrolysis. Purified phenol oxidase (laccase) from the white rot fungus Pleurotus ostreatus ( Po ) together with the mediator 2,2′‐azinobis(3‐ethylbenzthiazoline‐6‐sulfonate) (ABTS) displayed complete and rapid oxidative degradation of the nerve agents VX and Russian VX (RVX) and the insecticide analog diisopropyl‐Amiton with specific activity: k sp =2200, 667 and 1833 nmol min −1 mg −1 , respectively (pH 7.4, 37°C). A molar ratio of 1:20 for OP/ABTS and 0.05 M phosphate at pH 7.4 provided the highest degradation rate of VX and RVX. The thermostable laccase purified from the fungus Chaetomium thermophilium ( Ct ) in the presence of ABTS caused a 52‐fold slower degradation of VX with k sp =42 nmol min −1 mg −1 . The enzymatic biodegradation products were identified by 31 P‐NMR and GC/MS analysis.