title: Identification and functional analysis of a novel tryptophyllin peptide from the skin of the red-eye leaf frog, Agalychnis callidryas.
abstract: Amphibian skin has proved repeatedly to be a largely untapped source of bioactive peptides and this is especially true of members of the Phyllomedusinae subfamily of frogs native to South and Central America. Tryptophyllins are a group of peptides mainly found in the skin of members of this genus. In this study, a novel tryptophyllin (TPH) type 3 peptide, named AcT-3, has been isolated and structurally-characterised from the skin secretion and lyophilised skin extract of the red-eye leaf frog, Agalychnis callidryas. The peptide was identified in and purified from the skin secretion by reverse-phase HPLC. MALDI-TOF mass spectrometry and MS/MS fragmentation sequencing established its primary structure as: pGlu-Gly-Lys-Pro-Tyr-Trp-Pro-Pro-Pro-Phe-Leu-Pro-Glu, with a non-protonated molecular mass of 1538.19Da. The mature peptide possessed the canonical N-terminal pGlu residue that arises from post-translational modification of a Gln residue. The deduced open-reading frame consisted of 63 amino acid residues encoding a highly-conserved signal peptide of approximately 22 amino acid residues, an intervening acidic spacer peptide domain, a single AcT-3 encoding domain and a C terminal processing site. A synthetic replicate of AcT-3 was found to antagonise the effect of BK on rat tail artery smooth muscle and to contract the intestinal smooth muscle preparations. It was also found that AcT-3 could dose-dependently inhibit the proliferation of human prostate cancer cell lines after 72h incubation.
authors.affiliation: 1. Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy. Tianjin Medical University, Tianjin 300070, China ; 2. School of Pharmacy, Medical Biology Centre, Queen's University, Belfast BT9 7BL, Northern Ireland, UK.
authors.forename: Ran
authors.initials: R
authors.lastname: Wang
authors.affiliation: 2. School of Pharmacy, Medical Biology Centre, Queen's University, Belfast BT9 7BL, Northern Ireland, UK ; 3. School of Biomedical Science and Institute of Molecular Medicine, Huaqiao University, Xiamen 361021, Fujian, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: 2. School of Pharmacy, Medical Biology Centre, Queen's University, Belfast BT9 7BL, Northern Ireland, UK.
authors.forename: Tianbao
authors.initials: T
authors.lastname: Chen
authors.affiliation: 2. School of Pharmacy, Medical Biology Centre, Queen's University, Belfast BT9 7BL, Northern Ireland, UK.
authors.forename: Mei
authors.initials: M
authors.lastname: Zhou
authors.affiliation: 2. School of Pharmacy, Medical Biology Centre, Queen's University, Belfast BT9 7BL, Northern Ireland, UK.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.affiliation: 2. School of Pharmacy, Medical Biology Centre, Queen's University, Belfast BT9 7BL, Northern Ireland, UK.
authors.forename: Chris
authors.initials: C
authors.lastname: Shaw
mesh_terms: D000818:Animals; D001001:Anura / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D009842:Oligopeptides / Q000737:chemistry* / Q000494:pharmacology*; D010455:Peptides / Q000737:chemistry* / Q000494:pharmacology*; D051381:Rats; D012867:Skin / Q000737:chemistry*
chemical_list: D009842:Oligopeptides; D010455:Peptides; C048291:tryptophyllins
keywords: Agalychnis callidryas; anticancer effect; bradykinin antagonist; myotropic activities; proline-rich peptide