Cow κ-casein: Structure of the carbohydrate portion

The Chemical Structure of the Main Sugar Moiety Isolated from Bovine Whole Casein

“…33 . 34 ) Soon after the completion of our experiment, a work on the separation of tri-and tetrasaccharides from K-casein and on the determination of their chemical structures 6]-GalNAc) by alkali treatment and GLCmasspectrometry analysis was reported by Fournet et al 8 ) The structure of the trisaccharide proposed coincides well with ours. In their study, however, the partial structure between D-Gal and GalNAc was determined from gaschromatographic data on D-Gal and GalNAcItol, and the molar ratio was measured to be 1 : 0.45.…”

Characterization of caseinomacropeptides released from renneted raw and UHT treated milks

“…Such an observation has already been made by numerous authors: Sinkinson and Wheelock, 1970;Doi et al, 1979;Fournet et al, 1979;Jollès and Fiat, 1979;Addeo et al, 1984;Van Hooydonk et al, 1984. It has been attributed to a reduced accessibility to chymosin of the glycosylated sites of x-casein which would have higher electronegativity than the carbohydrate-free forms (Van Hooydonk et al, 1984).…”

Purification and Characterization of UDP-N-Acetylgalactosamine: κ-Casein PolypeptideN-Acetylgalactosaminyltransferase from Mammary Gland of Lactating Cow

“…K-Casein has mucin-type carbohydrate chains with the structures NANA-Gal-GaINAc-Thr, GalGaINAc(NANA)-Thr, and NANA-GalGaINAc(NANA)-Thr. 2,3) The observed microheterogeneity of Kcasein has been attributed to variations in the amount of carbohydrate chains. 4 ) We fractionated K-casein A into 9 subcomponents containing 0 to 8 sialic acids and 0 to 4 GaINAc, and found that the carbohydrate mOIetIes strongly enhance the micellestabilizing ability of K-casein.5) The carbohydrate chains of K-casein are synthesized by the successive action of three glycosyl transferases; UDP-N-acetylgalactosamine: K-casein polypeptide N-acetylgalactosaminyltransferase (Nacetylgalactosaminyltransferase ),.…”