Record Details
Field | Value |
---|---|
Title | A study of the function and physiological forms of ergosterol in Saccharomyces cerevisiae |
Names |
Adams, Bruce Gordon
(creator) Parks, Leo W. (advisor) |
Date Issued | 1968-04-25 (iso8601) |
Note | Graduation date: 1968 |
Abstract | A water-soluble complex containing ergosterol together with a component of yeast has been isolated. The complex can be isolated from commercial yeast extract to which ergosterol has been added or directly from whole yeast cells. The complexing agent from yeast extract is also capable of solubilizing cholesterol and a long chain hydrocarbon, hexadecane. The complexing agent has been shown to be a polysaccharide and appears to be composed solely of glucose subunits. The complexing agent does not appear to be glycogen. The binding between the sterol and the polysaccharide appears to be noncovalent. The complex is easily prepared and is stable in aqueous solution; ergosterol in this solution is metabolically available to yeast cells to which it is added. Data obtained from acid hydrolysis and extraction of yeast have demonstrated that routine saponification does not recover total sterol from the cells. This suggests the existence of a form of ergosterol resistant to saponification. Time course analyses of sterol synthesis by nonproliferating cell suspensions reveal an inverse relationship between the amounts of base labile and acid labile forms of sterol. These data give strong presumptive evidence for dual forms of ergosterol which are interconvertible according to the respiratory state of the cell. Experiments dealing with the effect of respiratory inhibitors on sterol synthesis in nonprofilerating cell suspensions suggest that the synthesis and physiological form of ergosterol is intimately related to the integrity of the respiratory apparatus and that the DNA encoding for the synthesis and regulation of ergosterol is located in the mitochondria. |
Genre | Thesis/Dissertation |
Topic | Saccharomyces |
Identifier | http://hdl.handle.net/1957/46628 |