Controlling the helical screw sense of peptides with C‐terminal L‐valine |
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| Authors: | Yosuke Demizu Nanako Yamagata Yukiko Sato Mitsunobu Doi Masakazu Tanaka Haruhiro Okuda Masaaki Kurihara |
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| Institution: | 1. Division of Organic Chemistry, National Institute of Health Sciences, Tokyo 158‐8501, Japan;2. Osaka University of Pharmaceutical Sciences, Osaka 569‐1094, Japan;3. Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852‐8521, Japan |
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| Abstract: | One chiral L ‐valine (L ‐Val) was inserted into the C‐terminal position of achiral peptide segments constructed from α‐aminoisobutyric acid (Aib) and α,β‐dehydrophenylalanine (ΔZPhe) residues. The IR, 1H NMR and CD spectra indicated that the dominant conformations of the pentapeptide Boc‐Aib‐ΔPhe‐(Aib)2‐L ‐Val‐NH‐Bn (3) and the hexapeptide Boc‐Aib‐ΔPhe‐(Aib)3‐L ‐Val‐NH‐Bn (4) in solution were both right‐handed (P) 310‐helical structures. X‐ray crystallographic analyses of 3 and 4 revealed that only a right‐handed (P) 310‐helical structure was present in their crystalline states. The conformation of 4 was also studied by molecular‐mechanics calculations. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd. |
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| Keywords: | α ‐aminoisobutyric acid α β ‐dehydrophenylalanine conformational analysis 310‐helix X‐ray diffraction molecular‐mechanics calculation |
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