Dimorphism in Candida albicans: contribution of mannoproteins to the architecture of yeast and mycelial cell walls

Abstract

Wall mannoproteins of the two (yeast and mycelial) cellular forms of Candida albicans were solubilized by different agents. Boiling in 2% (w/v) SDS was the best method, as more than 70% of the total mannoprotein was extracted. Over 40 different bands (from 15 to 80 kDal) were detected on SDS-polyacrylamide gel electrophoresis of this material. The residual wall mannoproteins were released after enzymic (Zymolyase and endogenous wall beta-glucanases) degradation of wall glucan, suggesting that they are covalently linked to this structural polymer. Four bands (of 160 kDal, 205 kDal and higher molecular mass) were observed in the material released from yeast walls but only the two smaller components were detected in the material obtained from mycelial walls. Moreover, the mannoproteins of high molecular mass, which are covalently linked in walls of normal cells, were not incorporated into walls of regenerating protoplasts, but non-covalently linked mannoproteins were retained from the beginning of the process.