Structure primaire du caseinomacropeptide des caseines κ porcine et humaine

Abstract

The amino acid sequence of porcine and human caseinomacropeptides (CMP), the C-terminal glycopeptide released from kappa-casein by chymosin at the initial step of milk coagulation, have been investigated. The complete amino acid sequence of porcine CMP and that of the first 59 amino acid residues of human CMP have been determined. Porcine and human CMPs contain 71 and likely 65 amino acid residues respectively. The extra hexapeptide 38-43 found in porcine CMP arises obviously from the duplication of the DNA fragment coding for the 6 preceding amino acids.

Rennets: their role in milk coagulation and cheese ripening

“…There are numerous Phe and a substantial number of Met residues in all milk proteins. Neither porcine nor human K-casein contains a Phe-Met bond [in both, the chymosinsensitive bond is Phe-He (Chobert et al, 1976;Brignon et al, 1985)], yet both are readily hydrolysed by calf chymosin, although more slowly than bovine K-casein; in contrast, porcine milk is coagulated more effectively than bovine milk by porcine chymosin (Foltmann, 1981), indicating that unidentified subtle structural features influence chymosin action. In rat and mouse K-casein; Met is replaced by Leu (Thompson et ai., 1985).…”

Separation of Recombinant Human Protein C from Transgenic Animal Milk Using Immobilized Metal Affinity Chromatography

“…o.S2' ~, y, and K variants (Table 1) 21,22,23. The amino acid length ranges from 167 for K casein to 220 for o.S2 casein.…”

The gene encoding αs1-casein is expressed in human mammary epithelial cells during lactation

“…Eisewhere, evidence for exon-skipping during the course of pre-m RNA splicing has been provided Menon et al, 1992). The existence of a human x-casein, the phosphoglycoprotein known to ensure the stability of the casein micelles against precipitation by Ca 2 + ions (Waugh, 1971 ), was definitively proven nearly 20 years aga (Chobert et al, 1976). Its amine acid sequence has been determined (Brignon et al, 1985a) and the relevant cD NA has been cloned and sequenced, starting from human mammary biopsies (Bergstrsôm et al, 1992).…”