Evaluation of sequence, structural, peptide and amino acid diversity of bacteriocin Nisin

Nisin is a bacteriocin from the group of lantibiotics and consists of ۳۴ amino acids that are mainly produced by different strains of Lactococcus lactis. Pathogen inhibition of nisin has been observed in bacteria such as Listeria monocytogenes, Staphylococcus aureus and Escherichia coli. Nisin contains the unusual amino acids lanthionine, methylanthionine, dihydrolanin, and dehydroaminobutyric acid. The antimicrobial mechanism of action of nisin is through two binding to lipid II as a precursor of bacterial cell wall peptidoglycan and inhibition of wall biosynthesis and the formation of pores in cell membranes and the release of essential ions. Because in the design of nisin peptide analogues, accurate knowledge of the sequence, structural, peptide and amino acid diversity of nisin is necessary, so in this study, the mentioned variations were performed using related databases including Bactibase, NCBI-Genome, Ensemble Bacteria, MBGD, BAGEL۴. The results showed that there are ۹ different variants of nisin including A, Z, Q, F, U, U۲, P, H, O. The diversity of nisins is due to substitution at amino acid positions of ۹, ۱۰, ۱۵, ۱۸, ۲۱, ۲۷, and ۳۰. Structurally, nisins are linear peptides with ۵ rings formed by disulfide bonds. The rings are necessary for maintenance and insensitivity to proteolytic degradation and resistance to thermal inactivation. Ring A in nisin is vital for biological activity. The results of this study can be used to explain the relationships between structure and function, stability, antimicrobial properties and directional mutagenesis in order to be used as a bioactive inhibitor of pathogens.

کلیدواژه ها:

Bacteriocin ، Nisin ، Sequence variability ، Structure variability