DISTRIBUTION OF PROTEIN-BOUND SULFHYDRYL GROUPS IN YEAST CELLS

Abstract

Young and old cultures of 12 yeasts have been stained by the Barrnett-Seligman histochemical procedure for localization of sulfhydryl groups. Thiol groups have been found distributed in the cytoplasm, but not in the cell wall. The intense staining of sulfhydryl groups by the specific stain was clearly showns in the slender thread of protoplasm between bud and mother cell. The intensity of staining in the proliferating cell was higher than in the resting cell; variations in thiol content between various yeast species were recorded. No decrease in thiol content of yeast spores, as compared with vegetative cells, has been found in Schizosaccharomyces octosporus, whereas the staining of yeast spores in Saccharomyces and Hansenula was found to be negligible. Implications of these findings are discussed.