Proteolytic activation of alpha,alpha-trehalose 6-phosphate synthase in Candida utilis.
Total trehalose 6-phosphate synthase activity increased in cell-free extracts from Candida utilis following short-term preincubation of the enzyme samples at 37 degrees C. This endogenous activation was prevented by the inhibitors of serine-type proteases, phenylmethylsulfonyl fluoride, antipain or chymostatin, but not by other protease inhibitors such as pepstatin. Fractionation of the cell extracts by Sephadex G-200 gel filtration revealed that the activity of one of the two synthase enzymes present in these cells was enhanced after the activation treatment. These observations indicate the existence of a proteolytically activatable enzyme form in the trehalose 6-phosphate synthase complex of this yeast in addition to the previously characterized enzyme, whose activity appears to be inactivated by reversible phosphorylation.
Vicente-Soler
J
J
Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, Spain.
Arguelles
J C
JC
Gacto
M
M
D002175:Candida / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D002850:Chromatography, Gel; D004789:Enzyme Activation / Q000187:drug effects; D005656:Fungal Proteins / Q000187:drug effects / Q000378:metabolism*; D005964:Glucosyltransferases / Q000378:metabolism*; D007700:Kinetics; D011480:Protease Inhibitors / Q000494:pharmacology; D013696:Temperature
D005656:Fungal Proteins; D011480:Protease Inhibitors; D005964:Glucosyltransferases; C023180:trehalose-6-phosphate synthase