Triprolines Pro-Pro-Pro-NH2 (4), Pro-Pro-D-Pro-NH2 (5), Pro-Pro(trans- 3-Me)-D-Pro-NH2 (6), and Pro-Pro(cis-3-Me)-D-Pro-NH2 (7) were made as conformationally constrained analogues of Pro-Leu-Gly-NH2. Triprolines 4-6 produced significant increases in the high- and low-affinity state ratio (R(H)/R(L)) of the dopamine receptor, but only 4 was found to increase apomorphine induced rotations in 6-hydroxydopamine-lesioned rats.
Bibliographical noteFunding Information:
Acknowledgment: This work was supportedin part by an NIH grant (NS20036)t o R.L.J. and an NIH predoctoratrl aineeshi(pG M07994)t o P.W.B. The authorsth ankT om Crick for masss pectraal nalyses.