J 2017

Catalytic Cycle of Haloalkane Dehalogenases Toward Unnatural Substrates Explored by Computational Modeling

MARQUES, Sérgio Manuel, Zuzana DUNAJOVÁ, Zbyněk PROKOP, Radka CHALOUPKOVÁ, Jan BREZOVSKÝ et. al.

Basic information

Original name

Catalytic Cycle of Haloalkane Dehalogenases Toward Unnatural Substrates Explored by Computational Modeling

Authors

MARQUES, Sérgio Manuel (620 Portugal, belonging to the institution), Zuzana DUNAJOVÁ (703 Slovakia, belonging to the institution), Zbyněk PROKOP (203 Czech Republic, belonging to the institution), Radka CHALOUPKOVÁ (203 Czech Republic, belonging to the institution), Jan BREZOVSKÝ (203 Czech Republic, belonging to the institution) and Jiří DAMBORSKÝ (203 Czech Republic, guarantor, belonging to the institution)

Edition

JOURNAL OF CHEMICAL INFORMATION AND MODELING, DC USA, AMER CHEMICAL SOC, 2017, 1549-9596

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10201 Computer sciences, information science, bioinformatics

Country of publisher

United States of America

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

Impact factor

Impact factor: 3.804

RIV identification code

RIV/00216224:14310/17:00095517

Organization unit

Faculty of Science

UT WoS

000408790100022

Keywords in English

MOLECULAR-DYNAMICS SIMULATIONS; FORCE-FIELD; DIRECTED EVOLUTION; SYNTHETIC PATHWAY; PRODUCT RELEASE; MECHANISM; KINETICS; LINB; BIODEGRADATION; PARAMETERS

Tags

Změněno: 29/3/2018 23:17, Ing. Nicole Zrilić

Abstract

V originále

The anthropogenic toxic compound 1,2,3-trichloropropane is poorly degradable by natural enzymes. We have previously constructed the haloalkane dehalogenase DhaA31 by focused directed evolution (Pavlova, M. et al. Nat. Chem. Biol. 2009, 5, 727-733), which is 32 times more active than the wild-type enzyme and is currently the most active variant known against that substrate. Recent evidence has shown that the structural basis responsible for the higher activity of DhaA31 was poorly understood. Here we have undertaken a comprehensive computational study of the main steps involved in the biocatalytic hydrolysis of 1,2,3-trichloropropane to decipher the structural basis for such enhancements. Using molecular dynamics and quantum mechanics approaches we have surveyed (i) the substrate binding, (ii) the formation of the reactive complex, (iii) the chemical step, and (iv) the release of the products. We showed that the binding of the substrate and its transport through the molecular tunnel to the active site is a relatively fast process. The cleavage of the carbon halogen bond was previously identified as the rate-limiting step in the wild-type. Here we demonstrate that this step was enhanced in DhaA31 due to a significantly higher number of reactive configurations of the substrate and a decrease of the energy barrier to the S(N)2 reaction. C176Y and V245F were identified as the key mutations responsible for most of those improvements. The release of the alcohol product was found to be the rate-limiting step in DhaA31 primarily due to the C176Y mutation. Mutational dissection of DhaA31 and kinetic analysis of the intermediate mutants confirmed the theoretical observations. Overall, our comprehensive computational approach has unveiled mechanistic details of the catalytic cycle which will enable a balanced design of more efficient enzymes. This approach is applicable to deepen the biochemical knowledge of a large number of other systems and may contribute to robust strategies in the development of new biocatalysts.

Links

GAP503/12/0572, research and development project
Name: Konstrukce syntetické metabolické dráhy pro degradaci důležitého environmentálního polutantu proteinovým a metabolickým inženýrstvím
Investor: Czech Science Foundation
LH14027, research and development project
Name: Nové koncepty a nástroje pro racionální design enzymů
Investor: Ministry of Education, Youth and Sports of the CR
LM2015047, research and development project
Name: Česká národní infrastruktura pro biologická data (Acronym: ELIXIR-CZ)
Investor: Ministry of Education, Youth and Sports of the CR, Czech National Infrastructure for Biological Data
LM2015051, research and development project
Name: Centrum pro výzkum toxických látek v prostředí (Acronym: RECETOX RI)
Investor: Ministry of Education, Youth and Sports of the CR
LM2015055, research and development project
Name: Centrum pro systémovou biologii (Acronym: C4SYS)
Investor: Ministry of Education, Youth and Sports of the CR
LO1214, research and development project
Name: Centrum pro výzkum toxických látek v prostředí (Acronym: RECETOX)
Investor: Ministry of Education, Youth and Sports of the CR
MUNI/M/1888/2014, interní kód MU
Name: Pokročilé hybridní metody studia transportních procesů v proteinech a jejich využití v designu biokatalyzátorů
Investor: Masaryk University, INTERDISCIPLINARY - Interdisciplinary research projects
4SGA8519, interní kód MU
Name: Rational design and engineering of enzyme gates (Acronym: BIOGATE)
Investor: South-Moravian Region, Incoming grants