A-o-Galactosidase

The relationship between the a-o-fucosidase and a-o-galactosidase activities in human and animal tissues, etc., has been investigated. ... 

The interaction of an alkali-stable polysaccharide from the cell surface of staphylococci with human fibrinogen has been modified by prior treatment of the polysaccharide with D-glucose oxidase, a-o-galactosidase, or jS-o-2-acetamido-2-deoxyglucosidase,... 

It has been shown that the a-D-galactosidase B from human liver also exhibits a-D-2-acetamido-2-deoxygalactosidase activity (p. 392). A highly purified fraction of a-o-galactosidase B from human liver was found to contain a-D-2-acetamido-2-deoxygalactosidase activity (Am 2-nitrophenyl 2-acetamido-2-deoxy-a-D-galactopyranoside 1.3 mM, Am 4-methylumbelliferyl a-D-galacto-pyranoside 6.8 mM). The hydrolysis of the latter substrate was completely... 

The release of )S-D-galactosidase from the vesicles of human intestinal brush-border membranes by various enzymes, particularly pancreatic proteases, has been studied. a-o-Galactosidases A and B have been extensively purified from human liver by classical procedures. In contrast to previous reports, it was shown that the A form is not converted into the B form on treatment with neuraminidase, although an apparent transformation of the A form into the B form was revealed by Cellogel electrophoresis. 

In order to account for the inability of many enzymes to bind the protonated form of the basic inhibitors or permanently cationic ones better than uncharged analogs (for example, yS-o-galactosidase from E. coli, and P-v>-glucosidase from almonds), it was proposed that the enzyme could proton-ate the inhibitor at the active site by a cationic acid (for example, protonated histidine). If proton transfer cannot occur, the attractive forces due to the carboxylate would be canceled by the repulsion from the cationic acid. Experimental evidence for this proposal is, however, still lacking. In fi-D-gn-lactosidase from E. coli, a tyrosine is presumed to be responsible for the protonation of substrates. ... 

Rossi, F., Charlton, C. A., and Blau, H. M. (1997). Monitoring protein-protein interactions in intact eukaryotic cells by O-galactosidase complementation. Proc. Natl. Acad. Sci. USA 94, 8405-8410. 

Calystegine Ni weak inhibitor of disaccharidase-type a-glucosidases and potent inhibitor of P-glucosidases (including cellobiase), lactase and o-galactosidase ... 

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