A protein homologous to glyceraldehyde-3-phosphate dehydrogenase is induced in the cell wall of a flocculent Kluyveromyces marxianus

Abstract

A protein with an apparent molecular weight of 37000 (p37) is present in very large amounts in the cell wall of iKluyveromyces marxianus, after the induction of flocculation of the yeast. This protein was isolated by preparative gel electrophoresis and its purity checked by SDS-PAGE and reverse-phase HPLC. SDS-PAGE, endoglycosidase-H treatment and peptide sequencing indicated that p37 is a glycoprotein with a high identity to cytosolic glyceraldehyde-3-phosphate dehydrogenase from Saccharomyces cerevisiae. Polyclonal antibodies were used for Western blot analysis and immunocytochemistry, which showed that p37 is present in the cell wall of non-flocculent K. marxianus and, therefore, is a constitutive protein of the cell wall.