Purification and properties of an oligo-1,6-D-glucosidase from an alkalophilic Bacillus species.
An isomaltose-hydrolyzing alpha-D-glucosidase from the alkalophilic Bacillus designated strain F5 was purified to an electrophoretically homogeneous state. The molecular weight of the purified glucosidase was 60,000 by SDS-poly(acrylamide) gel electrophoresis, and 63,000 by Sephacryl S-200 gel-filtration chromatography. The enzyme was most active for isomaltose at pH 6.0-6.5 and 45 degrees, and stable up to 50 degrees at pH 7.0 and in the range of pH 6.0-9.0 at 50 degrees by 10-min incubation. The apparent Vmax and Km values for isomaltose were 34.5 mumol.min-1.mg-1 of protein, and 3.33 mM. Panose and isomaltotriose are the best substrates for this enzyme. The restricted substrate specificity indicated the assignment of the enzyme to be an oligo-1,6-glucosidase (dextrin 6-alpha-glucanohydrolase; EC 3.2.1.10), but it was suggested that it could be a new type of oligo-1,6-glucosidase on the basis of its action on a series of (1----4)-alpha-malto-oligosaccharides.
Yamamoto
M
M
RIKEN Institute, Saitama, Japan.
Horikoshi
K
K
D001407:Bacillus / Q000201:enzymology*; D004795:Enzyme Stability; D006026:Glycoside Hydrolases / Q000302:isolation & purification*; D009834:Oligo-1,6-Glucosidase / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D013379:Substrate Specificity
D006026:Glycoside Hydrolases; D009834:Oligo-1,6-Glucosidase