Isolation and characterization of four antibacterial peptides from bovine hemoglobin

Peptic digestion of bovine hemoglobin at low degree of hydrolysis yields several intermediate peptide fractions after separation by reversed phase HPLC exhibiting antibacterial activity against Micrococcus luteus A270, Listeria innocua, Escherichia coli, and Salmonella enteritidis. From these fractions, four new antibacterial peptides were isolated and analyzed by ESI-MS/MS. Three of these peptides correspond to fragments of the alpha-chain of bovine hemoglobin: alpha 107-141, alpha 137-141, and alpha 133-141, and one peptide to the beta-chain: beta 126-145. The minimum inhibitory concentrations (MIC) of these peptides towards the four strains and their hemolytic activity towards bovine erythrocytes were determined. (c) 2006 Elsevier Inc. All rights reserved.