Hylins: Bombinins H Structurally Related Peptides from the Skin Secretion of the Brazilian Tree-Frog Hyla biobeba

Abstract

Two hemolytic peptides were isolated from the skin secretion of the Brazilian Hylidae frog Hyla biobeba, using reversed-phase chromatographic procedures. Hylins b1 and b2 exhibit short linear polypeptide chains, a large number of hydrophobic residues, amidated C termini and hemolytic properties. These two novel peptides are the first examples of bombinins H-like peptides isolated from anurans species not related to Bombina species.

Post-secretory events alter the peptide content of the skin secretion of Hypsiboas raniceps

“…To date, the biochemical characterization of the peptide content of the skin secretions of Hylanae frogs is sparse. Few studies have highlighted the presence of antimicrobial peptides, such as hylaseptin isolated from Hyla punctata [4] and hylins isolated from Hyla biobeba [5]. Building on these initial findings, a novel family of dermaseptin-related peptides, termed raniseptins, has been characterized from the hylid Hypsiboas raniceps [6].…”

“…Moreover, the antimicrobial activities of the peptide fragments were also investigated. Rsp-1 (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14) showed much lower or no antimicrobial action when compared to the intact Rsp-1. The MIC values were 85 and 170 lM against E. coli and P. aeruginosa respectively, and innocuous against S. aureus, whereas Rsp-1(15-29) lacked antimicrobial potential altogether ( Table 1).…”

“…The MIC values were 85 and 170 lM against E. coli and P. aeruginosa respectively, and innocuous against S. aureus, whereas Rsp-1(15-29) lacked antimicrobial potential altogether ( Table 1). The fact that Rsp-1 (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14) displayed weak antimicrobial potential contrasts with other reports that have shown that the first eighteen N-terminal residues of a related dermaseptin S1 isolated from Phyllomedusa sauvagei are solely responsible for the antimicrobial activity of the peptide [15]. Although it can be argued that the fourteen residues of Rsp-1 (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14) are not sufficient to spam a lipid bilayer, other studies have shown that shorter fragments of dermaseptin S3, also synthesized with a C-terminal amidation, still retain full potency against Gramnegative bacteria [14].…”

“…The fact that Rsp-1 (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14) displayed weak antimicrobial potential contrasts with other reports that have shown that the first eighteen N-terminal residues of a related dermaseptin S1 isolated from Phyllomedusa sauvagei are solely responsible for the antimicrobial activity of the peptide [15]. Although it can be argued that the fourteen residues of Rsp-1 (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14) are not sufficient to spam a lipid bilayer, other studies have shown that shorter fragments of dermaseptin S3, also synthesized with a C-terminal amidation, still retain full potency against Gramnegative bacteria [14]. In this sense, since a high positive charge content has been known to be important for antimicrobial activity, one possible explanation for the limited activity of Rsp-1 (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14) could be the presence of the negative charge of Asp-4, absent from t...…”

Combinatorial Synthesis and Directed Evolution Applied to the Production of α-Helix Forming Antimicrobial Peptides Analogues

“…The first is the search for new molecules of the innate defense system from host organisms [24,25]. Alternatively, antimicrobial peptides can be developed and optimized by combinatorial synthesis.…”