Side Chain Cyclization Based on Serine Residues: Synthesis, Structure, and Activity of a Novel Cyclic Analogue of the Parathyroid Hormone Fragment 1−11
作者:Andrea Caporale、Mattia Sturlese、Lorenzo Gesiot、Fabrizio Zanta、Angela Wittelsberger、Chiara Cabrele
DOI:10.1021/jm1008264
日期:2010.11.25
H-Aib-Val-Aib-Glu-Ile-Gln-Leu-Nle-His-Gln-Har-NH2 that contains two helix-stabilizing residues (Aib1,3). To increase the helical character and proteolytic stability of this linear peptide, we replaced Gln6,10 with (a) Lys6 and Glu10 to introduce a lactam bridge and (b) Ser6,10 to form a diester bridge upon cross-linking with adipic acid. These cyclopeptides were, respectively, 468-fold less and 12-fold more
甲状旁腺激素(PTH)的N端足以激活G蛋白偶联的PTH受体1(PTHR1)。显示纳摩尔效价的最短PTH类似物是十一肽H -Aib-Val-Aib-Glu-Ile-Gln-Leu-Nle-His-Gln-Har- NH 2,其中含有两个螺旋稳定残基(Aib 1,3)。为了增加该线性肽的螺旋特性和蛋白水解稳定性,我们用(a)Lys 6和Glu 10取代了Gln 6,10,以引入内酰胺桥和(b)Ser 6,10与己二酸交联形成二酯桥。这些环肽的有效激动剂分别比线性类似物少468倍和多12倍。尽管它们的效能不同,但所有三个类似物均采用相似的α-螺旋结构,如NMR和分子动力学研究所示。然而,与内酰胺部分相比,二酯桥可以更好地模拟线性PTH类似物中Gln 6和Gln 10侧链的取向和化学性质。这显然对于有效的受体活化很重要,并提供了对受体结合的配体构象的进一步了解。