Structure-receptor binding relationships of sarafotoxin and endothelin in porcine cardiovascular tissues.
The specific binding of 125I-sarafotoxin S6b was observed in the microsomal fractions from porcine thoracic aorta, and two vasoconstrictive peptides with strikingly homologous structures, sarafotoxin (SRT) and endothelin (ET), interact with a common receptor of the vasculature. The order of the potency of an each endothelin or sarafotoxin analogue as a competitor against 125I-sarafotoxin S6b binding was ET-1 greater than ET-2 greater than SRT S6b greater than ET-3 much greater than SRT S6c. The hydrophobic carboxyl-terminal tail and intramolecular disulfide bridges are essential for the binding activity. In addition, Ser4, Ser5 and Lys9 seem to be important for the activity while the 6th residue does not affect the activity.
Takasaki
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C
Department of Chemistry, Faculty of Science, Tohoku University, Sendai, Japan.
Aimoto
S
S
Takayanagi
R
R
Ohashi
M
M
Nawata
H
H
D000595:Amino Acid Sequence; D000818:Animals; D001013:Aorta, Thoracic / Q000378:metabolism*; D016232:Endothelins / Q000737:chemistry* / Q000378:metabolism; D008861:Microsomes / Q000378:metabolism; D008969:Molecular Sequence Data; D011950:Receptors, Cholinergic / Q000378:metabolism*; D018000:Receptors, Peptide; D012689:Sequence Homology, Nucleic Acid; D013329:Structure-Activity Relationship; D013552:Swine; D014662:Vasoconstrictor Agents / Q000737:chemistry* / Q000378:metabolism; D014757:Viper Venoms / Q000737:chemistry* / Q000378:metabolism
D016232:Endothelins; D011950:Receptors, Cholinergic; D018000:Receptors, Peptide; D014662:Vasoconstrictor Agents; D014757:Viper Venoms; C058085:sarafotoxin receptor; C057354:sarafotoxins s6