Colon 1-galactosidase

Redox reactions and hydrolysis are the predominant metabolic conversions triggered by the intestinal microflora. The primary reductive enzymes produced by the intestinal microflora are nitroreductase, deaminase, urea dehydroxylase, and azoreductase. The hydrolytic enzymes are p-glucuronidase, p-xylosidase, p-galactosidase, and ot-L-arabinosidase. Studies conducted by Macfarlane and coworkers have shown that proteolysis can also occur in the colon. More recent findings by the group indicate that bacterial fermentation of proteins in humans could account for 17% of the short-chain fatty acids in the cecum and for 38 /o in the sigmoid and the rectum. ... 

Raffinose is indigestible by humans because of a lack of an a-galactosidase and undergoes fermentation in the colon, causing production of carbon dioxide, hydrogen, and methane gases. ° ... 

The Km values of jS-D-acetamidodeoxy-galactosidase and -glucosidase activities in distal colonic tumours induced in rats by 1,2-dimethylhydrazine were shown to differ significantly from those of the same enzymes present in the colonic mucosa of control and tumour-bearing rats and in proximal colonic tumours. jS-D-Acetamidodeoxyglucosidase has been partially purified from epididymal spermatozoa and testes of mature rats sedimentation analysis revealed the presence of three isoenzymes (9.2, 8.1, and 6.45, respectively). Hormonal... 

Mucins.—Porcine colonic mucin has been desialylized by mild hydrolysis with acid the modified glycoprotein was used as a substrate for an endb-jS-D-galactosidase. ... 

To test for the effects of chemopreventive agents on COX-2 and/or iNOS transcriptional activity, we constructed a P-galactosidase (p-gal) reporter gene system in human colon cancer DLD-1 cells. 

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