The effects of alterations in fatty-acyl unsaturation in the plasma membrane of Saccharomyces cerevisiae NCYC 366 on the kinetics of accumulation of eight solutes were examined. The KT and Vmax values obtained for L-arginine and L-lysine accumultion were different for cells enriched with oleyl residues to those obtained for cells enriched with linoleyl residues, whilst for D-glucose only the Vmax value was altered. The KT and Vmax values obtained for accumulation of L-asparagine, and L-glutamine, and dihydrogen phosphate, sulphate and calcium ions were identical for cells enriched with either residue. Inclusion of palmitoleyl residues in the plasma membrane resulted in KT Vmax values for L-lysine and L-asparagine accumultion which were different to those obtained with cells enriched with either oleyl or linoleyl residues. The effects of temperature on accumulation of L-lysine and L-asparagine by cells with plasma membranes enriched with oleyl or linoleyl residues were also examined. The results are discussed in terms of specific lipid environments of proteins involved in the transport of those compounds. Many experiments yielded results which were independent of plasma-membrane compositional change but were interesting in themselves and therefore were worthy of comment.
|Date of Award||1981|