Yosuke Demizu, Hiroko Yamashita, Norikazu Yamazaki
Nov 20, 2013
Citations
0
Influential Citations
18
Citations
Journal
The Journal of organic chemistry
Abstract
We investigated the preferred conformations of two nonapeptides, Boc-(L-Leu-D-Leu-Aib)3-OMe (2) and its enantiomer Boc-(D-Leu-L-Leu-Aib)3-OMe (ent-2), four dodecapeptides, Boc-(L-Leu-D-Leu-Aib)4-OMe (3), Boc-(L-Leu-Aib-D-Leu)4-OMe (4), Boc-(Aib-L-Leu-D-Leu)4-OMe (5), and Boc-(L-Leu-Aib-D-Leu-Aib)3-OMe (6), and a decapeptide, Boc-L-Leu-(D-Leu-L-Leu-Aib)3-OMe (7), in solution and in the crystalline state. The nonapeptide 2 formed a right-handed (P) α-helix, and its enantiomer ent-2 formed a left-handed (M) α-helix. The dodecapeptides 3 and 5 were folded into (P) helices, and 4 formed an (M) helical structure. As for 6, roughly equivalent amounts of (P) and (M) helices were observed in solution, and two (M) α-helices were detected in the crystalline state. Furthermore, the decapeptide 7, which possesses four L-Leu residues and three D-Leu residues, was folded into an (M) α-helix.