A 20,000-dalton casein fragment in human milk.
A new peptide of 20,000 daltons was found in human milk as a constituent of the casein micelle. Enzymic digestion with plasmin or trypsin revealed that the peptide was identical with a degradation product of human beta-casein. The amino acid composition of the degradation product and the previously reported sequence in the N-terminal region of human beta-casein suggested that the peptide was a fragment of beta-casein lacking the C-terminal region. The thermal sensitivity of this peptide was higher than that of beta-casein, but the peptide lost the property of calcium-dependent precipitation, which intact beta-casein possesses.
Azuma
N
N
Kadoya
H
H
Yamauchi
K
K
D000595:Amino Acid Sequence; D002364:Caseins / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005341:Fibrinolysin / Q000494:pharmacology; D006801:Humans; D008894:Milk Proteins / Q000302:isolation & purification*; D008895:Milk, Human / Q000032:analysis*; D008970:Molecular Weight; D010446:Peptide Fragments / Q000302:isolation & purification*; D010447:Peptide Hydrolases / Q000378:metabolism
D002364:Caseins; D008894:Milk Proteins; D010446:Peptide Fragments; D010447:Peptide Hydrolases; D005341:Fibrinolysin