Purification and properties of alpha-mannosidase from bakers' yeast.
The yeast alpha-mannosidase [EC 3.2.1.24] was purified 1160-fold from the crude extract of the autolysate. The purified preparation was practically free from alpha-glucosidase, beta-glucosidase, alpha-galactosidase, beta-galactosidase, beta-mannosidase, and beta-N-acetylhexosaminidase activities. After the separation of yeast mannan during the purification procedures the enzyme became unstable but could be stored at 5 degrees C for three weeks with 50% loss of activity. The purified enzyme hydrolyzed both aryl and alkyl mannosides, but hydrolysis of yeast mannan proceeded slowly. Yeast mannan and Zn2+ increased the enzyme catalyzed hydrolysis of p-nitrophenyl mannoside, whereas NaN3, monoiodoacetate and methyl alpha-D-mannoside acted as inhibitors. The molecular weight was estimated to be 450,000 by gel filtration.
D006026:Glycoside Hydrolases / Q000378:metabolism; D007700:Kinetics; D008361:Mannosidases / Q000302:isolation & purification / Q000378:metabolism*; D008766:Methylmannosides / Q000494:pharmacology; D008970:Molecular Weight; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D013379:Substrate Specificity
D008766:Methylmannosides; D006026:Glycoside Hydrolases; D008361:Mannosidases