HLADILKOVA, J., Zbyněk PROKOP, Radka CHALOUPKOVÁ, Jiří DAMBORSKÝ and P. JUNGWIRTH. Release of Halide Ions from the Buried Active Site of the Haloalkane Dehalogenase LinB Revealed by Stopped-Flow Fluorescence Analysis and Free Energy Calculations. Journal of Physical Chemistry B. 2013, vol. 117, No 46, p. 14329–14335. ISSN 1520-6106. Available from: https://dx.doi.org/10.1021/jp409040u.
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Basic information
Original name Release of Halide Ions from the Buried Active Site of the Haloalkane Dehalogenase LinB Revealed by Stopped-Flow Fluorescence Analysis and Free Energy Calculations.
Authors HLADILKOVA, J. (203 Czech Republic), Zbyněk PROKOP (203 Czech Republic, belonging to the institution), Radka CHALOUPKOVÁ (203 Czech Republic, belonging to the institution), Jiří DAMBORSKÝ (203 Czech Republic, guarantor, belonging to the institution) and P. JUNGWIRTH (203 Czech Republic).
Edition Journal of Physical Chemistry B, 2013, 1520-6106.
Other information
Original language English
Type of outcome Article in a journal
Field of Study 10403 Physical chemistry
Country of publisher United States of America
Confidentiality degree is not subject to a state or trade secret
Impact factor Impact factor: 3.377
RIV identification code RIV/00216224:14310/13:00067017
Organization unit Faculty of Science
Doi http://dx.doi.org/10.1021/jp409040u
UT WoS 000327557700015
Keywords in English Haloalkane Dehalogenase LinB
Tags AKR, rivok
Changed by Changed by: prof. Mgr. Jiří Damborský, Dr., učo 1441. Changed: 9/4/2014 11:42.
Abstract
Release of halide ions is an essential step of the catalytic cycle of haloalkane dehalogenases. Here we describe experimentally and computationally the process of release of a halide anion from the buried active site of the haloalkane dehalogenase LinB. Using stopped-flow fluorescence analysis and umbrella sampling free energy calculations we showed that the anion binding is ion-specific and follows the ordering I- > Br- > Cl-. We have also addressed the issue of the protonation state of the catalytic His272 residue and its effect on the process of halide release. While deprotonation of His272 increases binding of anions in the access tunnel, we showed that the anionic ordering does not change with the switch of the protonation state. We also demonstrated that a sodium cation could relatively easily enter the active site, provided the His272 residue is singly protonated, and replace thus the missing proton. In contrast, Na+ is strongly repelled from the active site containing the doubly protonated His272 residue. Our study contributes towards understanding of the reaction mechanism of haloalkane dehalogenase enzyme family. Determination of the protonation state of the catalytic histidine throughout the catalytic cycle remains a challenge for future studies.
Links
GAP207/12/0775, research and development projectName: Strukturně-funkční vztahy haloalkan dehalogenas
Investor: Czech Science Foundation
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