title: Identification of envelope proteins of Candida albicans by vectorial iodination.
abstract: Intact Candida albicans yeast cells were radiolabelled with 125I, and cell wall, mixed membrane and soluble fractions prepared. The majority (67%) of the 125I was detected in the protein of the cell wall fraction at a specific activity 70-fold higher than that in the membrane or soluble fractions. SDS treatment of the cell wall fraction released 52% of the total protein but only 3% of the wall-bound 125I, and the extract was shown to be severely contaminated with cytosolic and membrane proteins. Zymolyase digestion of SDS treated walls liberated material which contained 93% of the 125I and on electrophoresis migrated as a single diffuse zone (average Mr 260 kD) typical of heterogenous mannoproteins. Protein (1.5%), GlcN (0.08%) and hexose (98.4%) content was measured and amino acid analysis showed enrichment in Ser (15.9%) and Thr (20.2%). These results indicate that the major iodinated protein(s) in the cell envelope is a 260 kD mannoprotein fraction containing both O-linked and Asn-linked oligosaccharides.
authors.affiliation: Department of Biochemistry, University of Otago, Dunedin, New Zealand.
authors.forename: C
authors.initials: C
authors.lastname: Molloy
authors.forename: M G
authors.initials: MG
authors.lastname: Shepherd
authors.forename: P A
authors.initials: PA
authors.lastname: Sullivan
mesh_terms: D000596:Amino Acids / Q000032:analysis; D002176:Candida albicans / Q000032:analysis* / Q000648:ultrastructure; D002458:Cell Fractionation; D002473:Cell Wall / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D005656:Fungal Proteins / Q000032:analysis*; D006867:Hydrolases; D007455:Iodine; D008562:Membrane Glycoproteins / Q000032:analysis; D012967:Sodium Dodecyl Sulfate
chemical_list: D000596:Amino Acids; D005656:Fungal Proteins; D008562:Membrane Glycoproteins; C025363:mannoproteins; D012967:Sodium Dodecyl Sulfate; C037833:zymolyase; D007455:Iodine; D006867:Hydrolases