Plasmin digest of κ-casein as a source of antibacterial peptides. Issue 2 (May 2014)

• Record Type: Journal Article
• Authors: Sedaghati, Marjaneh; Ezzatpanah, Hamid; Boojar, Masoud Mashhadi Akbar; Ebrahimi, Maryam Tajabadi; Aminafshar, Mehdi
• Is Part Of: Journal of dairy research. Volume 81:Issue 2(2014)
• Page Start: 245
• Page End: 251
• Publication Date: 2014-05
• Subjects: Dairying -- Periodicals; Dairying -- Research -- Periodicals; 636.214205
• DOI: 10.1017/S0022029914000120
• Languages: English
• ISSNs: 0022-0299

Abstract

<abstract abstract-type="normal"> <title> <x content-type="archive" xml:space="preserve">Abstract</x> </title> <p>This study investigated the antibacterial properties of plasmin, the plasmin hydrolysis of bovine κ-casein and the fractions (named κC1, κC2, κC3, κC4, and κC5) liberated from it using RP-HPLC. The target bacteria were <italic>Escherichia coli, Staphylococcus aureus</italic> (pathogenic), <italic>Lactobacillus casei</italic> and <italic>Lactobacillus acidophilus</italic> (probiotic). Three peptides (kC1, kC3, and kC4) were found to have antibacterial activity, with κC3 peptide being the most active. The plasmin digest of bovine κ-casein proved to be stronger than any of its fractions in terms of antibacterial potential. Measurement of the minimum inhibitory concentration (MIC) showed that Gram-positive bacteria are generally more sensitive to antibacterial activity than Gram-negative bacteria. The MIC of nisin, as a bacteriocin peptide, was also measured. The three antibacterial peptides were identified using LC-Mass. The molecular mass of kC1, kC3, and kC4 corresponded to the f(17–21), f(22–24), and f(1–3) of bovine κ-casein, respectively. It was also found that the positive charge and hydrophobicity of a peptide are not key factors in antibacterial activity. On the whole, the present study demonstrated that the plasmin digest of κ-casein has a high antibacterial potential and can be considered as a natural antibacterial agent in the food chain.</p> </abstract>