Physical Sciences and Mathematics Commons^™

Conformational Motion Associated With Catalysis In Indole-3-Glycerol Phosphate Synthase From S. Solfataricus, Tomasz Kurcon

Theses, Dissertations and Culminating Projects

Indole-3-glycerol phosphate synthase from Sulfolobus solfataricus (SsIGPS) belongs to a broad family of (βα)₈-barrel enzymes. It catalyzes the fifth step in tryptophan biosynthesis, converting l-(o-carboxylphenylamino)-l-deoxyribulose-5-phosphate (CdRP) to indole-3-glycerol phosphate (IGP). Site selective mutagenesis was used to introduce a single cysteine in two loops near the active site, generating two recombinant proteins, each containing a single cysteine handle. The two construct were labeled, each with two different thiol-reactive probes generating four labeled constructs that were used for this study. Steady-state kinetic parameters of the labeled mutants and the wild type SsIGPS were well characterized using fluorescence spectroscopy. Subsequent experiments …