Structural characterization of tachykinins (neuropeptide gamma, neurokinin A, and substance P) from a reptile, Alligator mississipiensis.
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-NH2. 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 gamma 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 sequence shows one substitution (Tyr for His4) compared with mammalian neuropeptide gamma. 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.
D000489:Alligators and Crocodiles / Q000502:physiology*; D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000378:metabolism; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D008969:Molecular Sequence Data; D015288:Neurokinin A / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D011863:Radioimmunoassay; D017386:Sequence Homology, Amino Acid; D013373:Substance P / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D015320:Tachykinins / Q000096:biosynthesis / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism
D010446:Peptide Fragments; D015320:Tachykinins; C059905:tachykinin neuropeptide gamma; D013373:Substance P; D015288:Neurokinin A