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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@article{1170226, author = {Hladilkova, J. and Prokop, Zbyněk and Chaloupková, Radka and Damborský, Jiří and Jungwirth, P.}, article_number = {46}, doi = {http://dx.doi.org/10.1021/jp409040u}, keywords = {Haloalkane Dehalogenase LinB}, language = {eng}, issn = {1520-6106}, journal = {Journal of Physical Chemistry B}, title = {Release of Halide Ions from the Buried Active Site of the Haloalkane Dehalogenase LinB Revealed by Stopped-Flow Fluorescence Analysis and Free Energy Calculations.}, volume = {117}, year = {2013} }
TY - JOUR ID - 1170226 AU - Hladilkova, J. - Prokop, Zbyněk - Chaloupková, Radka - Damborský, Jiří - Jungwirth, P. PY - 2013 TI - Release of Halide Ions from the Buried Active Site of the Haloalkane Dehalogenase LinB Revealed by Stopped-Flow Fluorescence Analysis and Free Energy Calculations. JF - Journal of Physical Chemistry B VL - 117 IS - 46 SP - 14329–14335 EP - 14329–14335 SN - 15206106 KW - Haloalkane Dehalogenase LinB N2 - 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. ER -
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. \textit{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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