Effect of Hg2+ on HydSL Hydrogenase of the Purple Sulfur Bacteria Thiocapsa roseopersicina BBS

摘要

The inhibitory effect of mercury(II) chloride on the activity and structure of the hydrogenase Thiocapsa roseopersicina BBS was studied. The kinetics of hydrogenase inactivation in the presence of different inhibitor concentrations was determined. The irreversible nature of Hg2+ action was established, and hydrogenase inhibition constants at different temperatures were determined. The presence of this inhibitor in enzyme solution significantly reduced its stability and caused denaturation at temperatures above 50 degrees C. In the process of enzyme incubation with Hg2+, the absorption band fades in the visible region of the spectrum, indicating the destruction of iron-sulfur clusters. Comparative analysis of the infrared Fourier spectra of hydrogenase without the addition and after incubation with inhibitor indicates the destruction of the NiFe active center.