title: Characterization of the host-defense peptides from skin secretions of Merlin's clawed frog Pseudhymenochirus merlini: insights into phylogenetic relationships among the Pipidae.
abstract: The family Pipidae comprises the genera Hymenochirus, Pipa, Pseudhymenochirus, Silurana, and Xenopus but phylogenetic relationships within the family are unclear. Peptidomic analysis of norepinephrine-stimulated skin secretions from Pseudhymenochirus merlini Chabanaud, 1920, the single species within the genus Pseudhymenochirus, led to identification of 13 host-defense peptides with antimicrobial activity. Two peptides (hymenochirin-1Pa and -1Pb) show structural similarity to hymenochirin-1B from Hymenochirus boettgeri and eight peptides (hymenochirin-5Pa, -5Pb, -5Pc, -5Pd, -5Pe, -5Pf, 5Pg and -5Ph) are structurally similar to each other and to hymenochirin-5B from H. boettgeri. Two peptides differing by a single amino acid (IKIPSFFRNILKKVGKEAVSLM/I AGALKQS), termed pseudhymenochirin-1Pa and -1Pb, and pseudhymenochirin-2Pa (GIFPIFAKLLGKVIKVASSLISKGRTE) do not resemble host-defense peptides previously isolated from pipid frogs. Hymenochirin-5Pe was the most abundant peptide in the secretions and hymenochirin-1Pa the most potent against Staphylococcus aureus (MIC=2.5μM) and Escherichia coli (MIC=10μM). The data support a close phylogenetic relationship between Hymenochirus and Pseudhymenochirus that is distinct from the Xenopodinae (Xenopus+Silurana) clade with Pipa sister-group to all other extant pipids.
authors.affiliation: Department of Biochemistry, College of Medicine and Health Sciences, United Arab Emirates University, 17666 Al-Ain, United Arab Emirates. Electronic address: jmconlon@uaeu.ac.ae.
authors.forename: J Michael
authors.initials: JM
authors.lastname: Conlon
authors.forename: Manju
authors.initials: M
authors.lastname: Prajeep
authors.forename: Milena
authors.initials: M
authors.lastname: Mechkarska
authors.forename: Laurent
authors.initials: L
authors.lastname: Coquet
authors.forename: Jérôme
authors.initials: J
authors.lastname: Leprince
authors.forename: Thierry
authors.initials: T
authors.lastname: Jouenne
authors.forename: Hubert
authors.initials: H
authors.lastname: Vaudry
authors.forename: Jay D
authors.initials: JD
authors.lastname: King
mesh_terms: D000595:Amino Acid Sequence; D029845:Amphibian Proteins / Q000737:chemistry* / Q000494:pharmacology; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry* / Q000494:pharmacology; D055598:Chemical Phenomena; D004926:Escherichia coli / Q000187:drug effects; D010802:Phylogeny; D010884:Pipidae / Q000145:classification / Q000378:metabolism*; D012867:Skin / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000187:drug effects; D014981:Xenopus / Q000145:classification* / Q000235:genetics / Q000378:metabolism
chemical_list: D029845:Amphibian Proteins; D023181:Antimicrobial Cationic Peptides; C000603832:pseudhymenochirin-1Pb peptide, Pseudhymenochirus merlini; C000603833:pseudhymenochirin-2Pa peptide, Pseudhymenochirus merlini
keywords: Antimicrobial peptide; Frog skin; Hymenochirus; Pipidae; Pseudhymenochirus