Purification, structural characterization, and myotropic activity of endothelin from trout, Oncorhynchus mykiss.
Endothelin (ET) from a nontetrapod species has never been characterized, either structurally or biologically. A single molecular form of trout ET with 21-amino-acid residues was isolated in pure form from an extract of the kidney of the steelhead trout, Oncorhynchus mykiss and its primary structure established as Cys-Ser-Cys-Ala-Thr-Phe-Leu-Asp-Lys-Glu10-Cys-Val-Tyr-Phe-Cys-His- L eu-Asp-Ile-Ile20-Trp. This amino acid sequence shows only three substitutions (Ala4-->Ser, Thr5-->Ser, and Phe6-->Trp) compared with human ET-2, demonstrating that the structure of the peptide has been well conserved during evolution and that the pathway of posttranslational processing of preproendothelin in the trout is probably similar to that in mammals. Synthetic trout ET produced concentration-dependent constrictions of isolated rings of vascular tissue from trout efferent branchial artery (EBA; pD2 = 7. 90 +/- 0.06, n = 5), caeliacomesenteric artery (pD2 = 8.03 +/- 0. 04, n = 4), anterior cardinal vein (ACV; pD2 = 8.57 +/- 0.25, n = 4), and rat abdominal aorta (AO; pD2 = 8.86 +/- 0.08, n = 7). Trout and rat vessels were more sensitive to mammalian ET-1 than to trout ET (pD(2) for human ET-1 in: EBA = 9.12 +/- 0.14; ACV = 9.90 +/- 0.15; AO = 8.86 +/- 0.08), but there was no significant difference in the maximum tension produced by either peptide in these vessels.
Wang
Y
Y
Regulatory Peptide Center, Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska 68178, USA.
Olson
K R
KR
Smith
M P
MP
Russell
M J
MJ
Conlon
J M
JM
D000595:Amino Acid Sequence; D000818:Animals; D001012:Aorta, Abdominal; D001158:Arteries; D019332:Endothelin-1 / Q000494:pharmacology; D019333:Endothelin-2 / Q000737:chemistry / Q000494:pharmacology; D016232:Endothelins / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D008322:Mammals; D008638:Mesenteric Arteries; D008969:Molecular Sequence Data; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000502:physiology; D017686:Oncorhynchus mykiss; D051381:Rats; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology; D014680:Veins
D019332:Endothelin-1; D019333:Endothelin-2; D016232:Endothelins