Structural characterization of tachykinins (neuropeptide γ, neurokinin A, and substance P) from a reptile, Alligator mississipiensis

Yunxia Wang, Finbarr O'Harte, J. Michael Conlon

Research output: Contribution to journalArticle

23 Scopus citations


An extract of the whole brain of the alligator (Alligator mississipiensis) contained very high concentrations of substance P-like immunoreactivity (405 pmol/g wet tissue) and neurokinin A-like immunoreactivity (514 pmol/g), as measured with antisera raised against the mammalian peptides. The primary structure of alligator substance P was established as: Arg-Pro-Arg-Pro-Gln-Gln-Phe-Phe-Gly-Leu-Met-NH... This sequence is the same as that of chicken substance P and shows one substitution (Arg for Lys3) as compared with mammalian substance P. The neurokinin A-like immunoreactivity was separated into two components. Neuropeptide y was the most abundant peptide and its primary structure was established as Asp-Ala-Gly-Tyr-Gly-Gln-Ile-Ser-His-Lys-Arg-His-Lys-Thr-Asp-Ser-Phe-Val-Gly-Leu-Met-NH2. This sequences shows one substitution (Tyr for His4) compared with mammalian neuropeptide y. The second component was identical to mammalian neurokinin A. A peptide with the chromatographic properties of mammalian neuropeptide K was not identified in the extract.

Original languageEnglish (US)
Pages (from-to)277-286
Number of pages10
JournalGeneral and Comparative Endocrinology
Issue number2
Publication statusPublished - Nov 1992


ASJC Scopus subject areas

  • Animal Science and Zoology
  • Endocrinology

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