Synthesis of yeast wall glucan

Area of Science:

• Biochemistry
• Cell Biology
• Microbiology

Background:

• Saccharomyces cerevisiae is a model organism for studying eukaryotic cell wall synthesis.
• Understanding the enzymes involved in polysaccharide biosynthesis is crucial for cell wall integrity.

Purpose of the Study:

• To investigate the effect of toluene-ethanol treatment on Saccharomyces cerevisiae.
• To identify and characterize glucan synthetase activity in yeast membranes.

Main Methods:

• Permeabilization of Saccharomyces cerevisiae using toluene and ethanol.
• Assay of glucan synthetase activity using UDP-[U-14C]glucose.
• Isolation of membrane preparations via differential centrifugation.

Main Results:

• Toluene-ethanol treatment unmasked glucan synthetase activity.
• Approximately 60% of the synthesized polymer was identified as beta-(1 to 3)glucan.
• 14C incorporation was localized to particulate membrane fractions, with no activity found in isolated particles.

Conclusions:

• The study identified a membrane-associated glucan synthetase activity in Saccharomyces cerevisiae.
• This activity is responsible for the synthesis of beta-(1 to 3)glucan, a major cell wall polysaccharide.
• The treatment also revealed an independent mannosyl transfer activity.