Antimicrobial peptides (AMPs) are metabolic inhibitors that target bacterial membranes. A number of groups are involved in the structure-function studies of AMPs. Some groups are also engaged in the development of new AMPs. The peptides can be tailored for a variety of applications. They can enhance food shelf life and provide anti-proteolytic activity.
Peptides are attracted to phospholipid membranes of bacteria. This interaction leads to antimicrobial action. However, at high concentrations, peptides can disrupt the bilayer. In turn, these disruptions cause membrane defects. AMPs can be designed to withstand these changes in the membrane.
There are two main types of AMPs. They can be either cationic or amphiphilic. Cationic peptides have a positive charge. They also have a hydrophobic core. These amphiphilic peptides contain three or four hydrogen bonds.
Amphiphilic peptides are known to have broad-spectrum antimicrobial activity. They are also susceptible to cleavage by trypsin-like proteases. Besides, these AMPs can be engineered for enhanced thermostability.
The best peptide design shows good antibacterial activity against five different bacterial species. The best peptides are stable against pH and temperature.
A b-hairpin BBI is a common molecule in natural cationic antibacterial peptides. It is found as 8, 16, and 24 kDa proteins. Each peptide is composed of a central trypsin inhibitory loop and a cluster of hydrophobic residues. These residues form a disulfide bridge and contribute to the stability and inhibition of peptides.
The d-Phe-2-Abz turn motif is one of the most important motifs in the synthesis of cationic amphiphilic peptides. This turn motif can be used to generate b-hairpin libraries.