title: Exo-(1----3)-beta-glucanase, autolysin and trehalase activities during yeast growth and germ-tube formation in Candida albicans.
abstract: Exo-(1----3)-beta-glucanase, beta-glucosidase, autolysin and trehalase were assayed in situ in Candida albicans during yeast growth, starvation and germ-tube formation. Cell viability, germ-tube formation, intracellular glucose-6-phosphate dehydrogenase and beta-glucosidase were unaffected in cells incubated in 0.1 M-HC1 for 15 min at 4 degrees C. However, in situ trehalase, (1----3)-beta-glucanase and autolysin activities in acid-treated cells decreased by 95, 50 and 35% respectively, indicating that these enzymes are, in part, associated with the cell envelope. Trehalase activity increased throughout yeast growth and remained elevated during the first hour of incubation for germ-tube formation. All of the in situ trehalase activity in starved yeast cells could be measured without the permeabilizing treatment. beta-Glucosidase activity declined throughout yeast growth and did not alter during germ-tube formation. Both the (1----3)-beta-glucanase and autolysin activities were optimal at pH 5 X 6, inhibited by gluconolactone and HgCl2, and maximal at 15-16 h during yeast growth. Although autolysin activity increased by 50-100% when starved yeast cells were incubated for germ-tube formation, the in situ (1----3)-beta-glucanase remained constant. When acid-treated starved yeast cells were similarly induced, in situ (1----3)-beta-glucanase increased 100% over 3 h of germ-tube formation. Yeast cells secreted (1----3)-beta-glucanase into the growth medium. This was highest in early exponential phase cultures (34% of the maximum in situ activity) and declined throughout growth. (1----3)-beta-Glucanase was also secreted into the medium during germ-tube formation and this represented 80-100% of the in situ activity in germ-tube forming cells. Both secretion of (1----3)-beta-glucanase and germ-tube formation were inhibited by 2-deoxyglucose, ethidium bromide, trichodermin and azaserine.
mesh_terms: D000581:Amidohydrolases / Q000378:metabolism*; D002176:Candida albicans / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development; D043326:Glucan 1,3-beta-Glucosidase; D005959:Glucosidases / Q000378:metabolism*; D006851:Hydrochloric Acid / Q000494:pharmacology; D007700:Kinetics; D009238:N-Acetylmuramoyl-L-alanine Amidase / Q000378:metabolism*; D014198:Trehalase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D001617:beta-Glucosidase / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D005959:Glucosidases; D001617:beta-Glucosidase; D014198:Trehalase; D043326:Glucan 1,3-beta-Glucosidase; D000581:Amidohydrolases; D009238:N-Acetylmuramoyl-L-alanine Amidase; D006851:Hydrochloric Acid