Purification and characterization of an exo-1,4-beta-galactanase from a strain of Bacillus subtilis.
An arabinogalactan 4-beta-D-galactanohydrolase was purified to a homogeneous state from the culture filtrate of a strain of Bacillus subtilis. The enzyme have a molecular mass of 36 kDa and an isoelectric point of pH 7.9. The enzyme is most active at around pH 6.5-7 and at 60 degrees C, and is stable between pH 6-10 and below 55 degrees C. Hg2+ and Cu2+ inhibit the activity. The enzyme hydrolyze soybean arabinogalactan which contains beta-1,4-galactosidic linkages in its main chain structure, but not other polysaccharides with beta-1,3-galactosidic linkages. The hydrolysis products from soybean arabinogalactan are predominantly galactobiose with a small amount of galactotetraose. The enzyme is an exo-enzyme and the ability to transfer galactobiose to other galactobiose molecules is indicated by the formation of galactotetraose.
Nakano
H
H
Osaka Municipal Technical Research Institute, Japan.
Takenishi
S
S
Kitahata
S
S
Kinugasa
H
H
Watanabe
Y
Y
D001412:Bacillus subtilis / Q000201:enzymology*; D001426:Bacterial Proteins / Q000302:isolation & purification; D002855:Chromatography, Thin Layer; D005697:Galactosides / Q000378:metabolism; D006026:Glycoside Hydrolases; D006863:Hydrogen-Ion Concentration; D007526:Isoelectric Point; D008670:Metals / Q000737:chemistry; D008970:Molecular Weight; D013379:Substrate Specificity; D013696:Temperature; D001616:beta-Galactosidase / Q000302:isolation & purification* / Q000378:metabolism
D001426:Bacterial Proteins; D005697:Galactosides; D008670:Metals; D006026:Glycoside Hydrolases; C066350:exo-1,4-beta-galactanase; D001616:beta-Galactosidase