Studies on the enzymology of sterol mehtyl transferase from Saccharomyces cerevisiae
| dc.creator | Marshall, Julie A. | |
| dc.date.accessioned | 2016-11-14T23:10:58Z | |
| dc.date.available | 2011-02-19T00:46:59Z | |
| dc.date.available | 2016-11-14T23:10:58Z | |
| dc.date.issued | 2001-05 | |
| dc.degree.department | Chemistry | en_US |
| dc.description.abstract | As an approach to understanding the enzymological details of sterol methylation catalysis in ergosterol biosynthesis, a kinetic analysis as well as an active site mapping study of the active center of the sterol methyl transferase (SMT) was pursued using a recombinant SMT from Saccharomyces cerevisiae. The following experiments were performed: i. Using initial velocity conditions and equilibrium dialysis to establish the kinetic constants, Km, Vmax, and K<i, respectively, the kinetic behavior of the native SMT and a set of site-specific mutants corresponding to either the sterol or AdoMet binding site was established, ii. Using native and mutant SMTs that exhibit differences in the complement of Ci/C2-activities the modulation of SMT activity by effectors such as ATP and ergosterol was determined, iii. Photoaffinity labeling of the active site using [^Us-methyl] AdoMet and sitespecific mutagenesis experiments were designed which successfully led to the identification of the AdoMet binding site on the SMT. The results of these studies and that of other studies from this laboratory involving the active site characterization of the sterol binding domain, are interpreted to imply that the SMT contains an active center in which there is a sterol and AdoMet binding motif spatially disposed to allow for a random bi bi kinetic mechanism in Cmethylation of a sterol acceptor molecule. A second distinct binding center on the SMT is considered for modulators. | |
| dc.format.mimetype | application/pdf | |
| dc.identifier.uri | http://hdl.handle.net/2346/22132 | en_US |
| dc.language.iso | eng | |
| dc.publisher | Texas Tech University | en_US |
| dc.rights.availability | Unrestricted. | |
| dc.subject | Saccharomyces cerevisiae | en_US |
| dc.subject | Enzymology | en_US |
| dc.subject | Sterols | en_US |
| dc.title | Studies on the enzymology of sterol mehtyl transferase from Saccharomyces cerevisiae | |
| dc.type | Dissertation |