Ranatensin-HL: A Bombesin-Related Tridecapeptide from the Skin Secretion of the Broad-Folded Frog, Hylarana latouchii.

Yan Lin,Songkun Su,Mei Zhou,Chris Shaw,Tianbao Chen,Lei Wang

doi:10.3390/molecules22071110

Abstract

Bombesin-related peptides are a family of peptides whose prototype was discovered in amphibian skin and which exhibit a wide range of biological activities. Since the initial isolation of bombesin from Bombina bombina skin, diverse forms of bombesin-related peptides have been found in the skins across Anura. In this study, a novel bombesin-related peptide of the ranatensin subfamily, named ranatensin-HL, was structurally-characterised from the skin secretion of the broad-folded frog, Hylarana latouchii, through combination of molecular cloning and mass spectrometric methodologies. It is composed of 13 amino acid residues, pGlu-RAGNQWAIGHFM-NH2, and resembles an N-terminally extended form of Xenopus neuromedin B. Ranatensin-HL and its C-terminal decapeptide (ranatensin-HL-10) were chemically synthesised and subjected to in vitro smooth muscle assays in which they were found to display moderate stimulatory effects on rat urinary bladder and uterus smooth muscles with EC50 values in the range of 1–10 nM. The prepro-ranatensin-HL was highly homological to a bombesin-like peptide from Rana catesbeiana at both nucleotide and amino acid levels, which might provide a clue for the taxonomic classification of ranid frogs in the future.

Highlights

Amphibian skin has long been known as a delicate and multifunctional organ which has played a plethora of fundamental roles in their survival for millions of years
One common class of peptides found in amphibian skin is the bombesin-related peptides, whose prototype is represented by bombesin, a tetradecapeptide originally isolated from the skin of Bombina bombina by Anastasi et al as early as 1971 [4]
The primary structure of this peptide was analysed by MS/MS fragmentation sequencing and subsequently confirmed by molecular cloning of the precursor-encoding cDNA to eliminate the L/I ambiguity (Figure 2)

Summary

Introduction

Amphibian skin has long been known as a delicate and multifunctional organ which has played a plethora of fundamental roles in their survival for millions of years. Such roles include respiration, camouflage, temperature control and chemical defence against encountered predators and pathogens [1]. Camouflage, temperature control and chemical defence against encountered predators and pathogens [1] The latter function is dependent on the secretions of highly specialised granular glands spread on the dorsal skin surface which contain a multitude of biologically-active peptides including antimicrobials, anticarcinogens, pheromones, neuropeptides and protease inhibitors [2,3].

Methods

Results

Discussion

Conclusion