Liepkaula I K, Skuin'sh A A, Romanovskiĭ P Ia, Porunkevich E A, Ratkevich M P
Bioorg Khim. 1985 Sep;11(9):1157-66.
Modified corticotropin fragment - [Lys11 (Gly)]ACTH-(5-14)- and its cyclic analogue - [cyclo (Glu gamma----epsilon Lys (Gly)] ACTH-(5-14)-undecapeptides have been synthesized by classical approach. The cyclic structure has been fixed by amide bond between gamma-COOH group of glutamic acid and alpha-NH2 group of glycine coupled to the epsilon-NH2 group of lysine. Fragment condensation has been achieved by azide or dicyclohexylcarbodiimide methods. Cyclization has been performed using diphenylphosphorylazide. The melanotropic activity of the cyclicanalogue on isolated frog skin exceeds by two orders of magnitude that of the linear undecapeptide, however the steroidogenic activity in isolated cells of rat adrenal cortex is diminished by an order of magnitude as compared with that of the linear precursor. A similarity of the CD spectra for the cyclic ACTH peptides and their linear counterparts in water and trifluoroethanol points to the similarity and relative rigidity of their structures.
已通过经典方法合成了修饰的促肾上腺皮质激素片段 - [赖氨酸11（甘氨酸）]促肾上腺皮质激素 -（5 - 14）- 及其环状类似物 - [环（谷氨酸γ----ε - 赖氨酸（甘氨酸）]促肾上腺皮质激素 -（5 - 14）- 十一肽。环状结构通过谷氨酸的γ - COOH基团与与赖氨酸的ε - NH2基团偶联的甘氨酸的α - NH2基团之间的酰胺键固定。片段缩合通过叠氮化物或二环己基碳二亚胺方法实现。环化使用二苯基磷酰叠氮化物进行。环状类似物对离体青蛙皮肤的促黑素活性比线性十一肽高出两个数量级，然而，与线性前体相比，大鼠肾上腺皮质离体细胞中的类固醇生成活性降低了一个数量级。环状促肾上腺皮质激素肽及其线性对应物在水和三氟乙醇中的圆二色光谱相似性表明它们结构的相似性和相对刚性。
