| Literature DB >> 1280787 |
G Chassaing1, S Lavielle, A Brunissen, A Carruette, C Garret, F Petitet, M Saffroy, J C Beaujouan, Y Torrens, J Glowinski.
Abstract
Structural considerations led us to postulate that the introduction of the dipeptides DPro9-Pro10 and DPro9-MeLeu10 should lock the C-terminal tetrapeptide of SP in a type II' beta-turn structure, a prerequisite for antagonist activity. Indeed, as the GR 71251, [DPro9, Pro10, Trp11]SP was more potent in inhibiting the septide, (pA2 = 6.5), than the [Pro9]SP, (pA2 < or = 5), spasmogenic activity in the guinea-pig ileum bioassay. This result confirms that septide, [pGlu6, Pro9]SP(6-11), a peptide active in the guinea-pig ileum bioassay and practically devoid of binding potencies for the three specific NK-1, NK-2 and NK-3 tachykinin binding sites interacts with a tachykinin receptor different from the NK-1 receptor sensitive to [Pro9]SP. Interestingly enough, the reintroduction of the leucine side-chain in position 10 yielded [DPro9, MeLeu10, Trp11]SP, an antagonist, equipotent in inhibiting both the septide- and the [Pro9]SP-evoked contractile response in the guinea-pig ileum bioassay, (pA2 = 6.6).Entities:
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Year: 1992 PMID： 1280787 DOI： 10.1016/0143-4179(92)90081-7
Source DB: PubMed Journal: Neuropeptides ISSN： 0143-4179 Impact factor: 3.286