Glycoproteins colostrum

N.m.r.-spectroscopic studies have furthennore shown that sialyl-transferase from bovine colostrum preferentially incorporates sialyl residues into a-(2— 6) linkages of glycopeptides from oq-acid glycoprotein.162... 

Bezkorovainy, A. 1965. Comparative study of the acid glycoproteins isolated from bovine serum colostrum and milk whey. Arch. Biochem. Biophys. 110, 558-567. 

Bezkorovainy, A. 1967. Physical and chemical properties of bovine milk and colostrum whey M-l glycoproteins. J. Dairy Sci. 50, 1368. 

Bezkorovainy, A. and Grohlich, D. 1969. Separation of the bovine colostrum M-l glycoproteins into two components. Biochem. J. 115, 817-822. 

Other reports also support a role for bacterial lectins in natural infections. Sialylated glycoproteins, administered orally, protected colostrum-deprived, newborn calves against lethal doses of enterotoxigenic E. coli K99[158]. In a clinical trial in humans, patients with otitis externa (a painful swelling with secretion from the external auditory canal) caused by P. aeruginosa were treated at the site of infection with a solution of galactose, mannose and AT-acetylneuraminic acid. The results were fully comparable to those obtained with conventional antibiotic treatment [159]. 

The preponderance of B. bifidum in the faeces of breast-fed infants is due to the presence of stimulatory factors in human milk. The most important of these are N-acetylglucosamine-containing saccharides, referred to as bifidus factor I, which is present at high levels in human milk and colostrum and bovine colostrum but at very low concentrations in the milk of cows, goats and sheep. Human milk also contains several non-dialysable bifidus-promoting factors which are glycoproteins, referred to as bifidus factor II. Many of the glycoproteins have been isolated and characterized (see Fox and Flynn, 1992). 

C12H23NO10 341.314 Isol. from porcine gastric mucin, human milk, glycoproteins with human blood group A activity, goat colostrum and from fetuin. Growth factor for Lactobacillus bifidus. [a]g- +78.2 (3 min) +63.1 (3h) (c, 1.25 in H2O). 

An A-acetylneuraminic acid has been isolated from bovine submaxillary mucin and the urinary glycoprotein (urinary mucoprotein of Tamm and Horsfall) following the enzymic action of the influenza virus on the glycoproteins 108), Gynaminic acid, from milk and meconium appear to be identical to the A-acetylneuraminic acid (sialic acid ) from sheep submaxillary gland and different from that from bovine submaxillary glands and lactaminic acid from bovine colostrum 102b, 109),... 

The two sialyltransferase activities have identical pH optima and Grimes (1970) suggests that a single enzyme may be involved. However, the colostrum glycoprotein sialyltransferase and the salivary gland mucin sialyltransferase are believed to be separate enzymes (Roseman et al, 1966), the former attaching sialic acid to terminal galactose resi-... 

Milk and colostrum glycoproteins contain sialic acids. The caseins are the major milk proteins, but only x-casein is a glycoprotein, with 5% carbohydrate. It has been isolated from human, bovine, ovine and goat sources (see Kobata 1977). 

The specificity of a colostrum sialyltransferase was investigated by Van den Eijnden et al. (1980) using glycopeptides derived from asialo-aj-acid glycoprotein as substrates. The positional specificity as well as the branch specificity of the enzyme were studied. 

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