LAUSR

Antimicrobial peptides are ubiquitous in the multicellular organism and have served as defensive weapons for their successful evolution and throughout their life cycle. These peptides are short cationic amphiphilic polypeptide fewer than 50 amino acids containing either a few disulfides-linked cysteine units with a characteristic of β-sheet rich structure or linear α-helical conformations with the hydrophilic side chains in one side of the helical structure and the hydrophobic side chains on the opposite side. Antimicrobial peptide lysis bacteria either directly through cell surface damage by electrostatic interactions between cationic side chains of the peptide and negatively charged bacterial cell surface or indirectly by modulating the host-defense systems. Electrostatic interaction leads to bacterial cell membrane disruption followed by leakage of cellular components and finally bacterial cell death. Because of their unusual cell damage mechanism, antimicrobial peptides are effective against drug-resistance bacteria and thus may be beneficial over classical antibiotics in some cases. As of now, around 3000 natural antimicrobial peptides from six kingdoms (bacteria, archaea, protists, fungi, plants, and animals) have been isolated and sequenced. However, only a few of them are under clinical trials and/or in the commercial development stage for the treatment of bacterial infections caused by antibiotic-resistant bacteria. Moreover, the high structural complexity, poor pharmacokinetic properties, and low antibacterial activity of natural antimicrobial peptides hindering the drug development process. In order to overcome these hindrances researchers have become increasingly interested in modification and nature-inspired synthetic antimicrobial peptide. This article discusses some of the recent studies reported on the antimicrobial peptide.