作者:Upadhyayula S. Raghavender、Kantharaju、Subrayashastry Aravinda、Narayanaswamy Shamala、Padmanabhan Balaram
DOI:10.1021/ja9083978
日期:2010.1.27
pores and close-packed structures are formed in closely related pentapeptides. Enantiomorphic sequences, Boc-(D)Pro-Aib-Xxx-Aib-Val-OMe (Xxx = Leu, 1; Val, 2; Ala, 3; Phe, 4) and Boc-Pro-Aib-(D)Xxx-Aib-(D)Val-OMe ((D)Xxx = (D)Leu, 5; (D)Val, 6; (D)Ala, 7; (D)Phe, 8), yield molecular structures with a very similar backbone conformation but varied packing patterns in crystals. Peptides 1, 2, 5, and 6
具有填充和空孔以及紧密堆积结构的肽纳米管形成于密切相关的五肽中。对映体序列,Boc-(D)Pro-Aib-Xxx-Aib-Val-OMe (Xxx = Leu, 1; Val, 2; Ala, 3; Phe, 4) 和 Boc-Pro-Aib-(D)Xxx- Aib-(D)Val-OMe ((D)Xxx = (D)Leu, 5; (D)Val, 6; (D)Ala, 7; (D)Phe, 8),产生具有非常相似的分子结构骨架构象,但晶体中的堆积模式不同。肽 1、2、5 和 6 显示管状结构,分子沿结晶六重轴(c 轴)自组装,并显示横向蜂窝状排列(ab 平面)。两种形式的夹带水线已在 2 中表征:d(O...O) = 2.6 A 的 2a 和 d(O...O) = 3.5 A 的 2b。后者也在 6 (6a) 中观察到. 6 (6b) 的多晶型,从甲醇-水的溶液中生长,观察到在单斜晶系中结晶