αs2-casein f(165-181) [id=CAA0024]

Producer Organism : Native Protein : Production Method :
Sheep αs2-casein Enzymatic hydrolysis and Purification with LC method/Synthetic
Activity : Antibacterial
Target Organisms :

Gram-positive: Active against Listeria innocua CECT 910 T, Staphylococcus epidermidis CECT 231, Staphylococcus carnosus CECT 4491T, Enterococcus faecalis CECT 795 at 0.5 mM.

Gram-negative: Active against Escherichia coli ATCC 25922, Serratia marcescens CECT 854 at 0.5 mM.

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

Length : 18 Mass (Da): 2 368.69 Common Amino Acids : Y
Isolectric Point : 9.95 Net Charge : 3 Absent Amino Acids : CDEGHMNRTV
Basic Residues : 3 Acidic Residues : 0 Hydrophobic Residues : 6
Polar Residues : 5 Boman Index : -15.35 Hydropathy Index : -0.778
Aliphatic Index : 70.56 Instability Index : 0 Extinction Coefficient : 11460
Absorbance 280nm : 674.12

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 ovine alphas2-casein

Cited Entries: LFB0085, CAA0020, CAA0021, CAA0023, CAA0024, CAA0025, CAA0026

Authors:Lopez-Exposito, I., Gomez-Ruiz, J.A., Amigo, L., Recio, I.
Journal: International Dairy Journal 2006, 16(9).
CrossRef External Link
Abstract: The aim of this work was to isolate and identify antibacterial peptides present in a pepsin digest of ovine αs2-casein. A protein digest with antibacterial properties was first separated by ion exchange chromatography. The fractions most active against Escherichia coli ATCC 25922 were fractionated by semi-preparative RP-HPLC, and the identification of the active peptides was carried out by on-line and off-line RP-HPLC-ESI-MS/MS. Following this strategy, 10 different peptides were identified, all corresponding to the C-terminal region of the ovine αs2-casein. Four of them were chemically synthesized and showed antibacterial activity against several Gram-positive and Gram-negative bacteria. Among the synthesized peptides, ovine αs2-casein f(165181) exhibited the highest antibacterial potency against all bacteria tested. The antimicrobial activity was compared with that of other previously described peptides like lactoferricin and fragment f(183207) of bovine αs2-casein.
Keywords: [alpha]s2-Casein; Antibacterial peptide; Electrospray mass spectrometry; Ovine milk

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