Structure and Function Characterization of Antimicrobial Peptide from Brevibacillus laterosporus

Abstract:

In order to study the structure and function of antimicrobial peptide from Brevibacillus laterosporus S62-9，the molecular mass，amino acid sequence and secondary structure of antimicrobial peptide were analyzed by MALDI-TOF/TOF mass spectrometry and FT-IR. The results indicated that the molecular mass of the peptide is 1 602.004 4 Da，and the primary structure of the peptide contains eleven amino acid residues，L-Y-K-L-V-K-V-V-L-N-M with a choline and a tenuazonic acid connected to the N-terminal and the C-terminal， respectively. The secondary structure mainly consists of β-turn and random coil. Antimicrobial assay indicated that the peptide is able to inhibit the growth both Gram-positive and Gram-negative bacteria with the MIC values of 7.81 μg/mL and 7.81~62.5 μg/mL respectively. The peptide also can inhibit the growth of the Penicillium sp and Aspergillus niger with the MIC value of 31.25 μg/mL and 62.5 μg/mL，repectively. The hemolytic results showed that the peptide exhibited hemolytic activity below 10% at 62.5 μg/mL，and more than 80% at 125 μg/mL. In addition，the peptide showed high thermal and pH stability and a strong resisted proteinases.