Seeking the Source of Catalytic Efficiency of Lindane Dehydrochlorinase, LinA.
Herein we present the results of an in-depth simulation study of LinA and its two variants. In our analysis, we combined the exploration of protein conformational dynamics with and without bound substrates (hexachlorocyclohexane (HCH) isomers) performed using molecular dynamics simulation followed by the extraction of the most frequently visited conformations and their characteristics with a detailed description of the interactions taking place in the active site between the respective HCH molecule and the first shell residues by using symmetry-adapted perturbation theory (SAPT) calculations. A detailed investigation of the conformational space of LinA substates has been accompanied by desc…
Dehydrochlorination of Hexachlorocyclohexanes Catalyzed by the LinA Dehydrohalogenase. A QM/MM Study
The elucidation of the catalytic role of LinA dehydrohalogenase in the degradation processes of hexachlorocyclohexane (HCH) isomers is extremely important to further studies on the bioremediation of HCH polluted areas. Herein, QM/MM free energy simulations are employed to provide the details of the dehydrochlorination reaction of two HCH isomers (γ and β). In particular, the role of the protonation state of one of the catalytic residues-His73-is explored. Based on our calculations, two distinct minimum free energy pathways (concerted and stepwise) were found for γ-HCH and β-HCH. The choice of the reaction channel for the dehydrochlorination reactions of γ- and β-HCH was shown to depend on t…