ABSTRACT
The yeast cell envelope contains an important complement of enzymes. Studies on the enzymology of the yeast cell envelope have their beginning in turn of the century work on isolation and partial purification of ß-fructofuranosidase. The methodology for studying enzymes of the cell envelope is generally common to that used with cell-free extracts. An emerging concept is that periplasmic space enzymes, once generated, are probably not under sophisticated control mechanisms. The syntheses of periplasmic space enzymes are subject to repression, but, because they are simply restrained by the cell wall, it is not anticipated that they will be greatly influenced by surrounding compounds. The primary role of acid phosphatase in yeasts is the hydrolysis of external phosphate esters which do not penetrate the plasma membrane. The enzymology associated with the cell envelopes of dimorphic yeast-like organisms must surely contribute to yeast phase-mycelial phase interconversions which are important to the etiology of pathogens such as Candida albicans and Histoplasma capsulatum.
