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[Ala1,3,11,15]endothelin-1 analogs with ETB agonistic activity

1991; Elsevier BV; Volume: 179; Issue: 1 Linguagem: Inglês

10.1016/0006-291x(91)91367-l

1090-2104

Toshihiko Saeki, Masaki Ihara, Takahiro Fukuroda, Miho Yamagiwa, Mitsuo Yano,

Phosphodiesterase function and regulation

A linear peptide analog of endothelin (ET)-1, [Ala1,3,11,15]ET-1 (4AlaET-1), and its truncated peptide analogs were synthesized to study the structural requirements of ET-1 for the recognition of ETs-nonselective ETB receptors. ET-1 exhibited sub-nanomolar binding to two distinct ET receptor subtypes (ETA and ETB), but 4AlaET-1 bound to ETB with an affinity 1,700 times higher than that seen during binding to ETA. The truncated linear peptides 4AlaET-1(6–21), 4AlaET-1(8–21) and N-acetyl-4AlaET-1(10–21) still had high affinity for ETB, whereas 4AlaET-1(6–20) and 4AlaET-1(11–21) displayed remarkably reduced affinity for ETB. Therefore, ET-1 requires the Glu10-Trp21 sequence for ETB binding, but not the disulfide bridges. These ETB-binding peptides elicit endothelium-dependent vasorelaxation of porcine pulmonary arteries in parallel with the binding affinity for ETB, suggesting that they are ETB agonists.