title: Identity of soluble thiamin-binding protein with thiamin-repressible acid phosphatase in Saccharomyces cerevisiae.
abstract: Two secretory glycoproteins of Saccharomyces cerevisiae, a soluble thiamin-binding protein and a thiamin-repressible acid phosphatase, were shown to be repressed to a similar extent by excess thiamin in the growth medium. Thiamin-repressible acid phosphatase was co-purified throughout the purification of the soluble thiamin-binding protein. Purified and deglycosylated soluble thiamin-binding proteins exhibited both thiamin-binding and acid phosphatase activity on non-denaturing polyacrylamide gel electrophoresis. Heat treatment of the purified soluble thiamin-binding protein caused a decrease in both activities with a similar inactivation profile. Furthermore, two thiamin-repressible acid phosphatase-defective mutants isolated had no and decreased soluble thiamin-binding activity, respectively. From the results, it was concluded that the soluble thiamin-binding protein is identical to the thiamin-repressible acid phosphatase in S. cerevisiae.
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism*; D002352:Carrier Proteins / Q000032:analysis*; D004591:Electrophoresis, Polyacrylamide Gel; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins; D012995:Solubility; D013831:Thiamine / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D029701:Saccharomyces cerevisiae Proteins; C026989:thiamine-binding protein; D000135:Acid Phosphatase; C488913:PHO3 protein, S cerevisiae; C488916:PHO5 protein, S cerevisiae; D013831:Thiamine