Synthesis of a Type-VI?-Turn Peptide Mimetic and Its Incorporation into a High-Affinity Somatostatin Receptor Ligand
作者:Dieter Gramberg、Christoph Weber、Reto Beeli、Janice Inglis、Christian Bruns、John A. Robinson
DOI:10.1002/hlca.19950780614
日期:1995.9.20
synthesis of a cis-Phe-Pro dipeptide mimetic is described, which adopts a type-VIβ-turn conformation. In this mimetic, the α-positions of Phe and Pro are joined by a CH2CH2 bridge, thereby forming a fused bicyclic system, and fixing a geometry similar to that seen in cis-Phe-Pro units in protein crystal structures. The dipeptide mimetic 20 was synthesized in optically pure form starting from (R)-α-allylproline
描述了顺式-Phe-Pro二肽模拟物的合成,其采用VIβ-转角构象。在该模拟物中,Phe和Pro的α-位置通过CH 2 CH 2桥连接,从而形成稠合的双环系统,并固定了类似于在蛋白质晶体结构中的顺式-Phe-Pro单元中所见的几何形状。从(R)-α-烯丙基脯氨酸(6 ;方案1,3和4开始)以光学纯净的形式合成二肽模拟物20。),游离羧酸和Fmoc保护的N末端,从而允许使用标准固相方法将其掺入线性和环状肽中。将模拟物20并入环状生长抑素类似物环(-Phe = Pro-Phe-D-Trp-Lys-Thr-),其中Phe = Pro代表模拟物。该类似物显示出高亲和力(p IC 508.6)用于大鼠脑皮质膜上的生长抑素受体。根据水溶液中的NMR研究,可使用受限的动态模拟退火推论出该类似物可能的低能构象。发现的构象,包括在D-Trp-Lys处扭曲的II'型拐点,类似于在其他地方推导的环(-Phe-P