Identification of antibacterial peptides from ovine α<inf>s2</inf>-casein

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(165-181) 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(183-207) of bovine αs2-casein. © 2006 Elsevier Ltd. All rights reserved.

Año de publicación:

2006

Keywords:

• Antibacterial peptide
• α -casein s2
• Ovine milk
• Electrospray mass spectrometry

Fuente:

scopus