2002 Fiscal Year Final Research Report Summary
Role of Hydrogen Bond in Polypeptides - ^2HNMR Studies in the Lyotropic Liquid Crystalline State
| Project/Area Number |
13650959
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
高分子構造・物性(含繊維)
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| Research Institution | TOKYO INSTITUTE OF POLYTECHNICS |
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Principal Investigator |
ABE Akihiro TOKYO INSTITUTE OF POLYTECHNICS, 工学部, 教授 (50114848)
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| Co-Investigator(Kenkyū-buntansha) |
HIEJIMA Toshihiro TOKYO INSTITUTE OF POLYTECHNICS, 工学部, 講師 (30288112)
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| Project Period (FY) |
2001 – 2002
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| Keywords | Poly(L-glutamate) / Poly(L-aspartate) / Helix-Coil Transition / Monodisperse PBLG / Re-entrant Isopropic Phase / Intramolecular Hydrogen Bond / Helix Sense Inversion / Chemical Modification of Side Chain Terminals |
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| Research Abstract |
1. Monodisperse PBLG samples having DP of 25 〜 50 have been prepared by using a solid-state peptide synthesizer. The helix-coil transitions in a mixed solvent comprising CHCl_3 and DCA were followed by ^1H- and ^<13>C-NMR. These samples exhibited two separate chemical shifts over the entire biphasic region : one from the helical and the other from the coil part. These observations are in contraditoin to those previously reported by Nagayame et al.
2. The helix-sense inversion phenomena peculiar to poly(aspartic acid ester)s has been studies for systems such as poly (β-p-chlorobenzyl L-aspartate) and poly(β-pentafluorophenethyl L-aspartate). Chemical modifications at the sidechain terminal were found to cause appreciable changes in the solubility of polymers, and eventually the helix-helix transition temperatures were shifted. These results indicate that the stability of hydrogen bonds involved in the α-helix conformation sensitively alters with the sidechain structure as well as the character of the surrounding solvents. Further investigations are underway to elucidate these unique characteristics of the internal hydrogen-bonds.
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