J 2001

Reaction mechanism and stereochemistry of gamma-hexachlorocyclohexane dehydrochlorinase LinA

TRANTÍREK, Lukáš, Kamila HYNKOVÁ, Yuji NAGATA, Alexey MURZIN, Alena ANSORGOVÁ et. al.

Basic information

Original name

Reaction mechanism and stereochemistry of gamma-hexachlorocyclohexane dehydrochlorinase LinA

Authors

TRANTÍREK, Lukáš (203 Czech Republic), Kamila HYNKOVÁ, Yuji NAGATA, Alexey MURZIN, Alena ANSORGOVÁ (203 Czech Republic), Vladimír SKLENÁŘ (203 Czech Republic) and Jiří DAMBORSKÝ (203 Czech Republic)

Edition

Journal of Biological Chemistry, 2001

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10600 1.6 Biological sciences

Country of publisher

United States of America

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

RIV identification code

RIV/00216224:14310/01:00004145

Organization unit

Faculty of Science

UT WoS

000167474900011
Změněno: 28/5/2003 22:04, prof. Mgr. Jiří Damborský, Dr.

Abstract

V originále

g-hexachlorocyclohexane dehydrochlorinase (LinA) catalyses the initial steps in the biotransformation of the important insecticide g-hexachlorocyclohexane (g-HCH) by the soil bacterium Sphingomonas paucimobilis UT26. Stereochemical analysis of the reaction products formed during conversion of g-HCH by LinA was investigated by GC-MS, NMR, CD and molecular modeling. The NMR spectra of 1,3,4,5,6-pentachlorocyclohexene (PCCH) produced from g-HCH using either enzymatic dehydrochlorination or alkaline dehydrochlorination were compared and found to be identical. Both enantiomers present in the racemate of synthetic g-PCCH were converted by LinA, each at a different rate. 1,2,4-trichlorobenzene (1,2,4-TCB) was detected as the only product of the biotransformation of biosynthetic g-PCCH. 1,2,4-TCB and 1,2,3-TCB were identified as the dehydrochlorination products of racemic g-PCCH. d-PCCH was detected as the only product of dehydrochlorination of d-HCH. LinA requires the presence of a 1,2-biaxial HCl pair on a substrate molecule. LinA enantiotopologically differentiates two 1,2-biaxial HCl pairs present on g-HCH and gives rise to a single PCCH enantiomer 1,3(R),4(S),5(S),6(R)-PCCH. Furthermore, LinA enantiomerically differentiates 1,3(S),4(R),5(R),6(S)-PCCH and 1,3(R),4(S),5(S),6(R)-PCCH. The proposed mechanism of enzymatic biotransformation of g-HCH to 1,2,4-TCB by LinA consists of two 1,2-anti conformationally dependent dehydrochlorinations followed by 1,4-anti dehydrochlorination.

Links

GA203/97/P149, research and development project
Name: Studium molekulárních mechanismů biodegradačních reakcí - konstrukce QSBR modelů a proteinové inženýrství dehalogenas
Investor: Czech Science Foundation, Study of the molecular mechanisms of biodegradation reactions - construction of QSBR models and protein engineering of haloalkane dehalogenases
LN00A016, research and development project
Name: BIOMOLEKULÁRNÍ CENTRUM
Investor: Ministry of Education, Youth and Sports of the CR, Biomolecular Center
ME 276, research and development project
Name: Racionální re-design mikrobiálních enzymů podílejících se na degradaci toxických organických polutantů
Investor: Ministry of Education, Youth and Sports of the CR, Rational re-design of microbial enzymes involved in degradation of toxic organic pollutants.