Structure-activity relationships for the competitive angiotensin antagonist [sarcosine1, O-methyltyrosine4]angiotensin II (sarmesin)
作者:Mahesh H. Goghari、Kevin J. Franklin、Graham J. Moore
DOI:10.1021/jm00156a035
日期:1986.6
Ile8]ANG II were weaker antagonists (pA2 = 6.6 and 6.7, respectively) than [Sar1,Ile8]ANG II (pA2 apparent = 8.1) and, moreover, were reversible competitive antagonists. These findings demonstrate that the structural requirements for receptor blockade by sarmesin are remarkably stringent--modifications at positions 1, 4, and 8 markedly reduce the antagonist activity of this peptide.
竞争性血管紧张素拮抗剂[Sar1,Tyr(Me)4] ANG II(sarmesin)的类似物已通过固相法合成,其中肌氨酸-1,O-甲基酪氨酸-4和苯丙氨酸-8残基被修饰。在大鼠离体子宫试验中确定了所合成的23种肽的激动剂和拮抗剂的效力。在位置1,用Asp,Ala或Pro取代Sar会产生无活性的类似物,而对于所有研究的类似物,N末端氨基酸的缺失都会产生无活性的七肽。在位置4,用Tyr(Et),D-Tyr,D-Phe,Ile,Thr或Hyp取代Tyr导致无效的类似物,而用Phe取代则产生了强大的竞争性拮抗剂(pA2 = 7.9),该拮抗剂具有显着的竞争性。激动剂活性(22%)。对于位置8,[Sar1,Tyr(Me)4,Ile8] ANG II和[Sar1,Phe4,Ile8] ANG II是较[Sar1,Ile8] ANG II(pA2明显= 8.1)更弱的拮抗剂(分别为pA2 = 6.6和6