obligatory replacement resulted in an increased physiological specificity of [Gln2]TRH. The enhanced activity of conformationally restricted cyclic peptides compared to linear ones suggests that the biologically active conformation responsible for the antidepressant activity of linear TRH analogs is the conformation with X−Protrans-bond.
在三肽 Glp-Gln-Pro 的合成中观察到 Gln(Asn)-Pro-NH2 容易内酰胺化,形成具有二酮
哌嗪结构的环状二肽(具有 X-Protrans 键的线性三肽的构象片段的模拟物) -NH2 通过在甲状腺激素(Glp-His-Pro-NH2,TRH)及其结构类似物 [Asn2]TRH 的合成中用必需的类似谷
氨酰胺替换组
氨酸来修饰。在合成的肽的质谱图中揭示了对应于 Glp 和 Pro
氨基酸残基的离子峰。测定所得化合物的
生物学特性,表明强制置换导致 [Gln2]TRH 的生理特异性增加。