title: A structural and functional analogue of a Bowman-Birk-type protease inhibitor fromOdorrana schmackeri.
abstract: Frog skin secretions contain complex peptidomes and peptidic protease inhibitors that are one of the biologically and structurally described groups of components. In the present study, by use of molecular 'shotgun' cloning and LC MS/MS fractionation sequencing, a novel Bowman-Birk-type heptadecapeptide (AALKGCWTKSIPPKPCF-amide), namedOdorranaschmackeriTrypsinInhibitor (OSTI), with a canonical Cys6-Cys16disulfide bridge, was isolated and identified in piebald odorous frog (O. schmackeri) skin secretion. A synthetic replicate of OSTI-exhibited trypsin inhibitory activity with aKivalue of 0.3 ± 0.04 nM and also a tryptase inhibitory effect with aKiof 2.5 ± 0.6 μM. This is the first time that this property has been reported for a peptide originating from amphibian sources. In addition, substituting lysine (K) with phenylalanine (F) at the presumed P1 position, completely abrogated the trypsin and tryptase inhibition, but produced a strong chymotrypsin inhibition with aKiof 1.0 ± 0.1 μM. Thus, the specificity of this peptidic protease inhibitor could be optimized through modifying the amino acid residue at the presumed P1 position and this novel native OSTI, along with its analogue, [Phe9]-OSTI, have expanded the potential drug discovery and development pipeline directed towards alleviation of serine protease-mediated pathologies.
authors.affiliation: Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast BT12 6BA, Northern Ireland, U.K. yuxin.wu@qub.ac.uk zhangyingqi08@sina.com.
authors.forename: Yuxin
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast BT12 6BA, Northern Ireland, U.K.
authors.forename: Qilin
authors.initials: Q
authors.lastname: Long
authors.affiliation: Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast BT12 6BA, Northern Ireland, U.K.
authors.forename: Ying
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, 123A Cater Mattil Hall, 2253 TAMU, College Station, TX 77843, U.S.A.
authors.forename: Shaodong
authors.initials: S
authors.lastname: Guo
authors.affiliation: Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast BT12 6BA, Northern Ireland, U.K.
authors.forename: Tianbao
authors.initials: T
authors.lastname: Chen
authors.affiliation: Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast BT12 6BA, Northern Ireland, U.K.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.affiliation: Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast BT12 6BA, Northern Ireland, U.K.
authors.forename: Mei
authors.initials: M
authors.lastname: Zhou
authors.affiliation: Department of Emergency Medicine, The First Hospital of Hebei Medical University, Shijiazhuang 050031, China yuxin.wu@qub.ac.uk zhangyingqi08@sina.com.
authors.forename: Yingqi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast BT12 6BA, Northern Ireland, U.K.
authors.forename: Chris
authors.initials: C
authors.lastname: Shaw
authors.affiliation: Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast BT12 6BA, Northern Ireland, U.K.
authors.forename: Brian
authors.initials: B
authors.lastname: Walker
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D009842:Oligopeptides / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology*; D011480:Protease Inhibitors / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D011898:Ranidae / Q000235:genetics / Q000378:metabolism*; D012867:Skin / Q000737:chemistry / Q000378:metabolism*; D014357:Trypsin; D014361:Trypsin Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D053802:Tryptases / Q000037:antagonists & inhibitors
chemical_list: D018076:DNA, Complementary; D009842:Oligopeptides; D011480:Protease Inhibitors; D014361:Trypsin Inhibitors; D014357:Trypsin; D053802:Tryptases
keywords: Bowman-Birk; Molecular cloning; Peptide; Skin secretion; Tryptase