title: Casein proteolysis in human milk: tracing the pattern of casein breakdown and the formation of potential bioactive peptides.
abstract: The protein and peptide fraction of human milk samples collected from mothers of pre- and full-term infants in the first week after parturition was analysed by use of liquid chromatography-mass spectrometry and tandem mass spectrometry. By characterising the peptide sequence, we defined the pathway of casein hydrolysis which leads to the formation of small peptides through intermediate oligopeptides. It was found that the action of a plasmin-like enzyme acting on specific lysine residues is the primary step in casein degradation. This is followed by endopeptidases and/or exopeptidases mediated cleavage of the oligopeptides which, in turn, produces a multiplicity of short peptides differing by one or more amino acid residues. In this process, a series of potentially bioactive peptides (opioid, phosphopeptides) and their precursors are produced.
authors.affiliation: Dipartimento di Scienza degli Alimenti, Università degli Studi di Napoli Federico II, Portici, Italy. ferranti@unina.it
authors.forename: Pasquale
authors.initials: P
authors.lastname: Ferranti
authors.forename: Maria Vittoria
authors.initials: MV
authors.lastname: Traisci
authors.forename: Gianluca
authors.initials: G
authors.lastname: Picariello
authors.forename: Antonella
authors.initials: A
authors.lastname: Nasi
authors.forename: Velia
authors.initials: V
authors.lastname: Boschi
authors.forename: Mario
authors.initials: M
authors.lastname: Siervo
authors.forename: Claudio
authors.initials: C
authors.lastname: Falconi
authors.forename: Lina
authors.initials: L
authors.lastname: Chianese
authors.forename: Francesco
authors.initials: F
authors.lastname: Addeo
mesh_terms: D000595:Amino Acid Sequence; D002364:Caseins / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D019281:Dimerization; D010450:Endopeptidases / Q000378:metabolism; D020689:Exopeptidases / Q000378:metabolism; D005260:Female; D005341:Fibrinolysin / Q000378:metabolism; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008239:Lysine / Q000378:metabolism; D013058:Mass Spectrometry; D008895:Milk, Human / Q000737:chemistry* / Q000201:enzymology; D008969:Molecular Sequence Data; D010449:Peptide Mapping; D010455:Peptides / Q000032:analysis*; D020539:Sequence Analysis, Protein; D012995:Solubility; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014238:Trichloroacetic Acid
chemical_list: D002364:Caseins; D010455:Peptides; D014238:Trichloroacetic Acid; D010450:Endopeptidases; D020689:Exopeptidases; D005341:Fibrinolysin; D008239:Lysine