Many antimicrobial peptides (AMPs) have multiple antimicrobial immunity effects. One such class of peptides is temporins. Temporins are the smallest (AMPs) found in nature and are highly active against gram-positive bacteria. Nowadays, there was a rapid increase in the availability of the 3D structure of proteins in PDB (protein data bank). The conserved residues and 3D structural conformations of temporins (AMPs) were still unknown. The present study explores the sequence analysis, alpha-helical structural conformations of temporins. The sequence of temporins was deracinated from APD3 database, the three-dimensional structure was constructed by homology modeling studies. The sequence analysis results show that the conserved residues among the peptide sequences, the maximum of the sequences are 70% alike to each other. The secondary structure prediction results revealed that 99% of temporin (AMPs) exhibited in alpha-helical form. The 3D structure speculated using RAMPAGE exposes the alpha-helical conformation in all temporins (AMPs). The phylogenetic analysis reveals the evolutionary relationships of temporins (AMPs), which are branched into seven clusters. As a result, we identified a list of potential temporin AMPs which docked to the antiviral protein (MERS-CoV), it shows good protein-peptide binding. This computational approach may serve as a good model for the rationale design of temporin based antibiotics.

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The host defense peptides or antimicrobial peptides (AMPs) often contain short sequence of amino acids, either positive or negatively charged and express broad-spectrum antibacterial, antiviral and antifungal activity. Many researchers had reported that tryptophan, arginine and proline rich AMPs have a promising source of next-generation antibiotics. Nowadays, AMPs are used as a possible therapeutic source for future antibiotics. In the present study, the amino acid sequences of 2924 AMPs belonging to various sources rich in Tryptophan, Proline and Arginine was chosen for investigation. The AMPs were further categorized according to their source, structure and antimicrobial activities. The AMPs with tryptophan, arginine, proline residues in abundance with maximum sequence length of 20 amino acids alone was obtained. Homology modeling was performed with PEP-FOLD and the modeled structures were evaluated using RAMPAGE to identify the structural information. Further, the stability of peptide in aqueous condition was probed using molecular dynamics simulations.

In recent years, the irrational use of antibiotics has escalated the evolution of multidrug-resistant (MDR) bacterial strains. The infectious diseases caused by these MDR bacterial strains remain a major threat to human health and have emerged as the leading cause of morbidity and mortality. The WHO and CDC have expressed serious concern regarding the continued increase in the development of multidrug resistance among bacteria. The antimicrobial resistance (AMR) poses a severe global threat of growing concern to human health and economic burden. Bacteria have developed the ability to resist antimicrobials by altering target site/enzyme, inactivation of the enzyme, decreasing cell permeability, increasing efflux due to over-expression of efflux pumps, target protection, target overproduction, and many other ways. The shortage of new antimicrobials and rapid rise in antibiotic resistance demands pressing need to develop alternate antibacterial agents.

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