Record Details
Field | Value |
---|---|
Title | A study of the biosynthesis of sterols and related compounds by a bovine aorta preparation |
Names |
Walsh, Marilyn Ruth
(creator) Gamble, Wilbert (advisor) |
Date Issued | 1967-08-17 (iso8601) |
Note | Graduation date: 1968 |
Abstract | Previous investigations of the biosynthesis of sterols by the arterial wall have shown that the intact aorta is capable of low level incorporation of labeled precursor into a sterol digitonide. The biosynthesis of sterols and related lipids by a cell-free preparation of bovine aorta was investigated in the present study. The cell-free system was the 60,000 x g supernatant of a Waring Blendor homogenate of aorta and 0.1 M phosphate nicotinamide buffer. When the 60,000 x g supernatant was incubated in the presence of adenosine triphosphate and mevalonic acid-2-C¹⁴, the non-saponifiable fraction (NSF) of the incubation mixture was radioactive. Acetate-2-C¹⁴ was not incorporated into the NSF. A sterol digitonide of low specific activity (60 to 237 counts per min per mg cholesterol) could be isolated from the NSF, but the major amount of radioactivity in the NSF was not digitonin precipitable. The 60,000 x g supernatant was capable of forming phosphomevalonic acid, mevalonic acid pyrophosphate, and isopentenyl pyrophosphate from MVA. Chromatography of the NSF on silicic acid-celite columns showed the labeled material to be slightly less polar than cholesterol. Samples of the labeled material isolated (by preparative layer chromatography) from large amounts of NSF did not give a positive Liebermann-Burchard reaction and did not form a 2, 4-dinitrophenylhydrazone. On silver nitrate impregnated layers of silicic acid, the labeled material appeared to be chromatographically similar to farnesol and squalene. Gas chromatography of a sample of labeled material showed all the radioactivity present in one peak with a retention time intermediate between the retention times of farnesol and squalene. The mass spectrum of the labeled material indicated the presence of compounds with m/e of 380, 384, and 386. The results of these experiments indicated that the major biosynthetic product is not cholesterol or other similar sterol, but may be a "prenol" of some kind. |
Genre | Thesis/Dissertation |
Topic | Steroids |
Identifier | http://hdl.handle.net/1957/47072 |