STRUCTURE-ACTIVITY RELATIONSHIPS OF HUMAN ALPHA-CGRP

心血管疾病是美国人死亡的主要原因 1989年美国有944，688人死亡，占美国人口的43%。 所有的死亡。血压的降低与降低的 高血压患者的发病率和死亡率。降钙素 基因相关肽是最有效的血管舒张肽， 自然.被确定为对其生物学特性重要的结构特征 活性是位置2和7之间的二硫键， 在位置8和22之间的螺旋，和在位置14的残基。表示“人”之义 α-CGRP（8-37）和[Tyr）O）-大鼠-α-CGRP（28-37）是竞争性的 对手。本提案的长期目标是深入了解 h-alpha-CGRP的构象和拓扑性质， 重要的是介导其在受体的生物学效应。的 一般的策略是（i）除去连续的末端氨基酸， 生物活性所需的，（ii）构象约束区域， 所述肽有利于推定的生物活性构象，和（iii）获得 确定为重要的位置的结构-活性谱 生物活性初步研究表明，没有氨基酸可以 从h-α-CGRP的C-末端去除，而不失去生物活性， 活动局部构象限制将被施加在C- 末端部分（残基27-37）通过将D-氨基酸取代为 稳定假定的β-弯曲。全球性的限制将强加于 通过用Pen残基取代Cys来提高二硫键的灵活性 残基37号残基的构效关系 以前被证明是必不可少的生物活性，将决定 受体在这个位置上能接受的官能团。的 拮抗剂h-alpha-CGRP（8- 将根据上述战略㈠、㈡和㈢确定。 拮抗剂的C-末端区域的相对重要性， 将比较天然肽。一种新的合成策略， 肽片段与MBHA树脂的缩合将用于 合成肽类似物。完全保护的碎片将被 按照凯泽的方案组装在肟树脂上。生物 类似物的活性和结合亲和力将在 胰腺腺泡细胞、肠系膜动脉和心房。从以下方面获得的见解： 该建议将使得能够设计有效的选择性激动剂， 证明可用作药理学的h-α-CGRP拮抗剂 用于表征新CORP受体的工具。而且他们 将作为设计治疗有用的 降低血压的药物。

Cardiovascular diseases are the principal cause of death in the United States today with 944,688 Americans dying in 1989 accounting for over 43% of all deaths. A reduction in blood pressure is associated with reduced morbidity and mortality of patients with high blood pressure. Calcitonin gene-related peptide is the most potent vasodilatory peptide occurring naturally. Structural features identified as important for its biological activity are the disulfide bridge between positions 2 and 7, the alpha- helix between positions 8 and 22, and the residue in position 14. human- alpha-CGRP (8-37) and [Tyr)O)-rat-alpha-CGRP (28-37) are competitive antagonists. The long term goal of this proposal is to gain insights into conformational and topographical properties of h-alpha-CGRP which are important for mediating its biological effects at its receptor. The general strategy is (i) to remove consecutive terminal amino acids not needed for biological activity, (ii) conformationally constrain regions of the peptide to favor putative bioactive conformations and (iii) obtain structure-activity profiles of positions identified as important for biological activity. Preliminary studies showed no amino acids can be removed from the C-terminus of h-alpha-CGRP without loosing biological activity. Local conformational constraints will be imposed on the C- terminal portion (residues 27-37) by substituting D-amino acids to stabilize putative beta-bends. Global constraints will be imposed on the flexibility of the disulfide bridge by substituting Pen residues for Cys residues. A structure-activity profile of residue 37, which we have previously shown to be essential for biological activity, will determine what functional groups the receptor will tolerate in this position. The importance of the C-terminal region of the antagonist, h-alpha-CGRP (8- 37), will be determined following strategies (i), (ii) and (iii) above. The relative importance of the C-terminal regions of the antagonist and the native peptide will be compared. A novel synthetic strategy involving the condensation of peptide fragments to a MBHA resin will be used to synthesize the peptide analogues. Fully protected fragments will be assembled on an oxime resin following Kaiser's protocols. Biological activity and binding affinity of the analogues will be assessed in pancreatic acinar cells, mesenteric artery and atria. Insights gained from this proposal will enable the design of potent selective agonists and antagonists of h-alpha-CGRP which will prove useful as pharmacological tools for the characterization of new CORP receptors. Furthermore, they will serve as excellent models for the design of therapeutically useful drugs to lower blood pressure.