Study on identification of antimicrobial peptides from trypsin hydrolysate of yak blood

Two eluting peaks including antimicrobial peptide component were isolated from trypsin zymolyte of yak blood, using the membrane binding property of antimicrobial peptides with bacteria cell, with Sephadex G-15 column, under conditions of 10 mmol/L phosphate buffer as eluent and flow rate 0.4 mL/min. The results of binding assay showed that the two novel antimicrobial peptides YakB-1 and YakB-2 were successfully isolated, combining the repeated purification with reverse phase high-performance liquid chromatography followed by antimicrobial activities assay. Antimicrobial activities indicated that both peptides clearly displayed a very impressive broad spectrum of activities against bacterial and fungus tested. Furthermore, the antimicrobial activities of YakB-2 were more powerful than that of YakB-1 against Gram-positive and Gram-negative bacterial. However, YakB-1 showed stronger antimicrobial activities against fungus than YakB-2.The results provide references for the development and utilization of yak blood resource.