κ-casein f(30-32) [id=CAK0009]

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

Gram-positive: Active against Listeria innocua CECT 910T, Staphylococcus carnosus CECT 231 at 5 mM.

Gram-negative: Active against Escherichia coli ATCC 25922, Serratia marcescens CECT 854 at 5 mM.

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

Length : 3 Mass (Da): 393.51 Common Amino Acids : YVL
Isolectric Point : 6.09 Net Charge : Absent Amino Acids : ACDEFGHIKMNPQRSTW
Basic Residues : 0 Acidic Residues : 0 Hydrophobic Residues : 2
Polar Residues : 1 Boman Index : 8.82 Hydropathy Index : 2.233
Aliphatic Index : 226.67 Instability Index : 0 Extinction Coefficient : 1490
Absorbance 280nm : 745

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

Identification of antibacterial peptides from bovine kappa-casein

Cited Entries: CAA0016, CAA0020, CAK0006, CAK0008, CAK0009, CAK0010, CAK0011, CAK0014, CAK0017, CAK0018, CAK0019, CAB0003, CAB0004, CAB0005

Authors:Lopez-Exposito, I., Minervini, F., Amigo, L., Recio, I.
Journal: Journal of Food Protection 2006, 69(12).
Abstract: The objective of the present study was to identify antimicrobial peptides present in several digests of commercial caseins with gastric enzymes. The most active hydrolysate against Escherichia coli ATCC 25922 and Listeria innocua CECT 910T corresponded to a pepsin digest of bovine kappa-casein. The protein digest was first separated by semipreparative high-performance liquid chromatography (HPLC), and the most active fractions were again subjected to a second chromatographic step. Finally, identification of the active peptides was carried out by online and offline HPLC-electrospray ionization-tandem mass spectrometry. By means of this technique, 21 peptides were identified in the active HPLC fractions. Although most were derived from bovine kappa-casein, some of the identified fragments corresponded to beta-casein and alpha(s)-casein fragments, a result of the presence of small amounts of these proteins in the preparation of kappa-casein. Some of the peptides identified were chemically synthesized and showed antibacterial effects against several gram-positive and gram-negative bacteria. Among the synthesized peptides, kappa-casein f(18-24), f(30-32), and f(139-146) were most effective against all bacteria tested. The antibacterial effect of these peptides is discussed in relation to their amino acid sequences.

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