Caerulein-and xenopsin-related peptides with insulin-releasing activities from skin secretions of the clawed frogs, Xenopus borealis and Xenopus amieti (Pipidae)

Osama K. Zahid, Milena Mechkarska, Opeolu O. Ojo, Yasser H.A. Abdel-Wahab, Peter R. Flatt, Mohammed A. Meetani, J. Michael Conlon

Research output: Contribution to journalArticlepeer-review

21 Citations (Scopus)

Abstract

Caerulein-related peptides were identified in norepinephrine-stimulated skin secretions of the tetraploid frog Xenopus borealis and the octoploid frog Xenopus amieti using negative ion electrospray mass spectrometry and their primary structures determined by positive ion tandem (MS/MS) mass spectrometry. X. borealis caerulein-B1 (pGlu-Gln-Asp-Tyr(SO3)-Gly-Thr-Gly-Trp-Met-Asp-Phe.NH2) contains an additional Gly5 residue compared with X. laevis caerulein and caerulein-B2 (pGlu-Asp-Tyr(SO3)-Thr-Gly-Trp-Met-Asp-Phe.NH2) contains a Gln2 deletion. X. amieti caerulein was identical to the X. laevis peptide. In addition, xenopsin, identical to the peptide from X. laevis, together with xenopsin-AM2 (pGlu-Gly-Arg-Arg-Pro-Trp-Ile- Leu) that contains the substitution Lys3→Arg were isolated from X. amieti secretions. X. borealis caerulein-B1, and X. amieti xenopsin and xenopsin-AM2 produced significant (P<0.05) and concentration-dependent stimulations of insulin release from the rat BRIN-BD11 clonal β cell line at concentrations ≥30nM. The peptides did not stimulate the release of lactate dehydrogenase at concentrations up to 3μM demonstrating that the integrity of the plasma membrane had been preserved. While their precise biological role is unclear, the caerulein- and xenopsin-related peptides may constitute a component of the animal's chemical defenses against predators.

Original languageEnglish
Pages (from-to)314-320
Number of pages7
JournalGeneral and Comparative Endocrinology
Volume172
Issue number2
DOIs
Publication statusPublished - Jun 1 2011

Keywords

  • Caerulein
  • Frog skin secretions
  • Insulin release
  • Mass spectrometry
  • Xenopsin
  • Xenopus

ASJC Scopus subject areas

  • Animal Science and Zoology
  • Endocrinology

Fingerprint

Dive into the research topics of 'Caerulein-and xenopsin-related peptides with insulin-releasing activities from skin secretions of the clawed frogs, Xenopus borealis and Xenopus amieti (Pipidae)'. Together they form a unique fingerprint.

Cite this