当前位置： SCI文献检索 > APPLIED MICROBIOLOGY AND BIOTECHNOLOGY期刊下所有文献 > Biotransformation of CL-20 by a dehydrogenase enzyme from Clostridium sp. EDB2.

Biotransformation of CL-20 by a dehydrogenase enzyme from Clostridium sp. EDB2.

Abstract：

:In a previous study, a marine isolate Clostridium sp. EDB2 degraded 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) under anaerobic conditions (Bhushan B, Halasz A, Thiboutot S, Ampleman G, Hawari J (2004c) Chemotaxis-mediated biodegradation of cyclic nitramine explosives RDX, HMX, and CL-20 by Clostridium sp. EDB2. Biochem Biophys Res Commun 316:816-821); however, the enzyme responsible for CL-20 degradation was not known. In the present study, we isolated and purified an enzyme, from strain EDB2, responsible for CL-20 degradation. The enzyme was membrane-associated and NADH-dependent and had a molecular weight of 56 kDa (with SDS-PAGE). N-terminal amino acid sequence of enzyme revealed that it belonged to dehydrogenase class of enzymes. The purified enzyme degraded CL-20 at a rate of 18.5 nmol/h mg protein under anaerobic conditions. Carbon and nitrogen mass balance of the products were 100 and 64%, respectively. In LC-MS-MS studies, we detected three different initial metabolites from CL-20, i.e., mono-nitroso derivative, denitrohydrogenated product, and double-denitrated isomers with molecular weight of 422, 393, and 346 Da, corresponding to presumed empirical formulas of C(6)H(6)N(12)O(11), C(6)H(7)N(11)O(10), and C(6)H(6)N(10)O(8), respectively. Identity of all the three metabolites were confirmed by using ring-labeled [(15)N]CL-20 and the nitro-group-labeled [(15)NO(2)]CL-20. Taken together, the above data suggested that the enzyme degraded CL-20 via three different routes: Route A, via two single electron transfers necessary to release two nitro-groups from CL-20 to produce two double-denitrated isomers; Route B, via a hydride transfer necessary to produce a denitrohydrogenated product; and Route C, via transfer of two redox equivalents to CL-20 necessary to produce a mono-nitroso derivative of CL-20. This is the first biochemical study which showed that CL-20 degradation can be initiated via more than one pathway.

journal_name

Appl Microbiol Biotechnol

journal_title

Applied microbiology and biotechnology

authors

Bhushan B,Halasz A,Hawari J

doi

10.1007/s00253-005-1992-4

subject

Has Abstract

pub_date

2005-12-01 00:00:00

pages

448-55

issue

eissn

0175-7598

issn

1432-0614

journal_volume

pub_type

杂志文章

在线工具

Biotransformation of CL-20 by a dehydrogenase enzyme from Clostridium sp. EDB2.