Antimicrobial peptide isolated from ovalbumin hydrolysate by immobilized liposome-binding extraction

Abstract

Antimicrobial peptides are of greatest potential as a new group of antibiotics. Enzymatic hydrolysis was performed using flavourzyme, pepsin, trypsin, neutrase, papain and alcalase to obtain antimicrobial peptides from ovalbumin. Pepsin hydrolysate exhibited the highest antimicrobial activity compared with other fractions. To purify and characterize antimicrobial peptide, an immobilized liposome-binding extraction method was developed, in which the liposome was regarded as a mimic biomembrane system. The immobilized liposome stationary phase was prepared, and the maximum adsorption capacity and Langmuir constant were 81.30 μM/g and 8.19 mL/mg, respectively. Four fragments were simultaneously predicted by the comparison between reverse-phase high-performance liquid chromatography chromatograms of pepsin hydrolysate before and after interaction with immobilized liposome membrane. A novel cationic antimicrobial peptide named Opep2 was sequenced as RVASMASEKMKI. In addition, antimicrobial mode experiments showed that Opep2 interacted with cell wall membrane and caused potassium efflux, nucleotide leakage and ultimately cell death. Because of the high efficiency and procedural simplicity, the immobilized liposome-binding extraction method could be more efficient for the screening of antimicrobial peptides than conventional methods, which provides scientific references for antimicrobial peptide production.