BIOL 77 |
| The enzyme, 2-(2'-hydroxyphenyl)benzenesulfinate desulfinase (HPBS desulfinase) enzyme catalyzes the cleavage of the aromatic carbon-sulfur bond of 2-(2'-hydroxyphenyl) benzenesulfinate (HPBS) to form hydroxybiphenyl and sulfite. HPBS desulfinase is the final and rate limiting enzyme in the desulfurization of the dibenzothiophene, an organosulfur contaminant in fossils fuels. The HPBS desulfinase gene from Nocardia asteroides A3H1 was cloned into a pGEX vector and soluble protein was obtained by coexpression with GroEL. Spectrofluorimetric assays were carried out to characterize the recombinant HPBS desulfinase. The characterization included measuring kinetic parameters, testing the effects of varying pH and temperature on the enzyme, and measuring the effects of metals and inhibitors. The parameters of the recombinant enzyme are similar to those of the native enzyme purified from Rhodococcus erythropolis strain sp. IGTS8. Solvent isotope studies, chemical modification studies and site directed mutagenesis experiments support the previously proposed chemical mechanism for this novel enzyme. |
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Frontiers in Chemical Biology
5:00 PM-7:00 PM, Sunday, August 19, 2007 BCEC -- Exhibit Hall - B2, Poster
Division of Biological Chemistry |