De Novo Design of Antiviral and Antibacterial Peptides with Varying Loop Structures
- *Corresponding Author:
- Guangshun Wang
Department of Pathology and Microbiology
University of Nebraska Medical Center
986495 Nebraska Medical Center
Omaha, NE 68198-6495, USA
E-mail: [email protected]
Received Date: October 13, 2011; Accepted Date: November 05, 2011; Published Date: December 10, 2011
Citation: Wang G, Buckheit KW, Mishra B, Lushnikova T, Buckheit RW (2011) De Novo Design of Antiviral and Antibacterial Peptides with Varying Loop Structures. J AIDS Clinic Res S2:003. doi:10.4172/2155-6113.S2-003
Copyright: © 2011 Wang G, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Although the rate of new HIV infections has been declining, AIDS continues to be one of the leading causes of death worldwide. The lack of an effective HIV vaccine makes it necessary to develop alternative strategies, such as the development of topical microbicides, to prevent transmission. Antimicrobial peptides represent promising microbicide candidates. Previously, we succeeded in enhancing the anti-HIV activities of several peptides that form helical structures based on the bioinformatic results learned from the antimicrobial peptide database. This study showed that Lys-to-Arg alterations also improved the HIV inhibitory activity of thanatin which is known to form a β-hairpin structure. Using a previously reported de novo designed HIV inhibitory peptide GLR-19 as the starting template, loop structures of varying sizes were generated by restraining a disulfide bond at different positions. The thanatin-mimicking constructs are referred to as GLRC peptides since they are composed of only four amino acid residues G, L, R, and C. While GLRC-2, the peptide with a medium-sized loop structure, was most potent against HIV-1 and HSV-2, GLRC-3, with the small loop structure, was most potent against Escherichia coli K12. Thus, the efficacy of the GLRC peptides is microbe dependent. Further terminal sequence truncation of GLRC-2 reduced antimicrobial activity against both viruses and bacteria. It appears that the high antiviral potency of GLRC-2 is related to high hydrophobicity, although a wide-range correlation is lacking. In addition, GLRC-2, which is more active against viruses, is also more resistant to the action of chymotrypsin. Therefore, GLRC-2, a novel peptide that acquired not only higher stability but also higher anti-HIV activity than the GLR-19 template, serves as the starting point for additional rounds of peptide engineering.