Record Details
The role of S-adenosylmethionine in the biosynthesis of ergosterol and related sterols in Saccharomyces cerevisiae
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | The role of S-adenosylmethionine in the biosynthesis of ergosterol and related sterols in Saccharomyces cerevisiae |
| Names |
Turner, Jan Ross
(creator) Parks, Leo W. (advisor) |
| Date Issued | 1965-05-11 (iso8601) |
| Note | Graduation date: 1965 |
| Abstract | An enzyme system was prepared from Saccharomyces cerevisiae, strain MCC, which carries out the transfer of the methyl group from S-adenosylmethionine or methionine to the side chain of yeast sterols. The cell-free system has been shown to be incapable of synthesizing ergosterol but carries out the synthesis of two as yet unidentified sterols which contain the methyl group of S-adenosylmethionine. Whole cells were shown to synthesize both ergosterol and the two sterols found in the cell-free system. By time course studies of pulsed methionine-methyl-C¹⁴ incorporation and by feeding experiments, it has been possible to show that the two sterols synthesized by the cell-free homogenate are precursors of ergosterol. The cell-free system requires for maximal activity ATP, MnCl₂, K₂CO₃, ascorbate, acetate and glucose-6-phosphate. When S-adenosylmethionine is the methyl donor, ATP is not necessary. The function of K₂CO₃, since it is not incorporated into sterol to any extent, was tested as a possible allosteric effector for this enzyme. Neither heating nor treatment with HgCl₂ produced a preparation which was insensitive to carbonate. Evidence was found that be two precursors have a double bond at C-22, as does ergosterol, but differ in the unsaturation of the ring system. |
| Genre | Thesis/Dissertation |
| Topic | Sterols |
| Identifier | http://hdl.handle.net/1957/47851 |
