Auswirkung der Änderung der Lipidzusammensetzung in Plasmamembranen von Saccharomyces cerevisiae durch Mutation auf das Phasen‐ und Mischungsverhalten der Lipidanteile

Abstract

Mutation of Saccharomyces cerevisiae leads to an alteration of the size and surface structure of the mutant cell. These phenomena are correlated with change in the lipid composition and hence membrane fluidity of the plasma membranes. Such alterations are in the fatty acyl constituents of phospholipids and glycolipids and include changes in the saturation or length of fatty acyl chains. Simultaneously, the "melting point" of phospholipid fractions, i.e. the temperature of the ordered-disordered phase transition and mixing behavior, changed. Consequently calorimetry on isolated phospholipid fractions extracted from plasma membranes is a useful analytical method to demonstrate directly such phase transitions and change in the mixing behavior of the cellular lipid fractions in connection with mutation. A correlation between the alteration of the lipid composition in the plasma membrane of strains of S. cerevisiae S 288 and its mutant VY 1160 is discussed.