β-casein f(50-56) [id=CAB0009]

Synonym: RCDT1

Producer Organism : Native Protein : Production Method :
Rabbit β-casein Enzymatic hydrolysis and Purification with LC method/Synthetic
Activity : Antibacterial
Target Organisms :

Gram-positive: Active against Staphylococcus lentus, Bacillus subtilis BGA at 3 mM.

NOTE: No activity against Streptococcus zooepidemicus, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 13883, Serratia marcescens ATCC 8100 at 3 mM .

Description :
Production method: Trypsin hydrolysis and purification with LC method/Synthetic.

Length : 7 Mass (Da): 894.38 Common Amino Acids : L
Isolectric Point : 7.55 Net Charge : 1 Absent Amino Acids : ACDFGIKMNPSTWY
Basic Residues : 2 Acidic Residues : 1 Hydrophobic Residues : 3
Polar Residues : 0 Boman Index : -18.05 Hydropathy Index : -0.414
Aliphatic Index : 152.86 Instability Index : 0 Extinction Coefficient :
Absorbance 280nm : 0

Wheel representation

Hydrophobicity plot

Red solid plot : values according to the hydrophobicity scale of Kyte and Doolittle (reference paper).
Yellow dashed plot : Experimentally determined hydrophobicity scale for proteins at membrane interfaces(reference paper).
Green dotted-dashed plot : prediction of transmembrane helices (reference paper). In this scale (unlike the others), more negative values reflect greater hydrophobicity.

Citation: 1

Antibacterial activity of casein-derived peptides isolated from rabbit (Oryctolagus cuniculus) milk

Cited Entries: CAB0009, CAB0010, CAA0022, CAS0002

Authors:Baranyi, M., Thomas, U., Pellegrini, A.
Journal: Journal of Dairy Research 2003, 70(02).
Abstract: Acid-precipitated rabbit ‘whole casein’ was digested by trypsin, chymotrypsin, pepsin, and clostripain to screen for possible peptides with antibacterial properties. The peptide fragments were separated by reversed-phase chromatography. The collected fractions were pooled and their antibacterial properties tested against Escherichia coli, Bacillus subtilis and Staphylococcus lentus. Three antibacterial peptide fragments derived from tryptic digestion of rabbit casein were isolated and identified. Their sequences were found as follows: HVEQLLR (residues 50–56 of β-casein), ILPFIQSLFPFAER (residues 64–77 of β-casein), and FHLGHLK (residues 19–25 of αs1-casein). The three peptides were synthesized and found to exert antibacterial effect against Gram positive bacteria only. Proteolytic digestion of rabbit casein by chymotrypsin, pepsin and clostripain yielded several peptide fragments with antibacterial activity. Since antibiotic peptides can be released from casein during the digestion of milk proteins, our results suggest a possible antibacterial function of rabbit caseins. It is conceivable that antibacterial peptides can be generated by endopeptidases of the mammalian gastrointestinal tract possibly providing protection for new-born rabbits against aggression of micro-organisms.
Keywords: Antibacterial; bioactive peptide; casein; milk; rabbit.

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