Conformation of Peptide Model Molecules in Alcohol-Water Mixtures and Its Pressure Dependence
| Project/Area Number |
15550016
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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 |
Physical chemistry
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| Research Institution | Saga University |
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Principal Investigator |
TAKAMUKU Toshiyuki Saga University, Faculty of Science and Engineering, Department of Chemistry and Applied Chemistry, Associate Professor, 理工学部, 助教授 (70291838)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2004: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 2003: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | Protein / Folding / Aliphatic alcohol / Fluoroalcohol / Cluster / SANS / Dehydration / Hydrophobic interaction / ペプチドモデル分子 / ハロゲノアルコール / NMR化学シフト / 赤外分光法 / 溶存挙動 / エタノール / トリフルオロエタノール / ケミカルシフト / 外部複基準法 / コンフォメーション |
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| Research Abstract |
The present investigation has focused on alcohol-induced protein folding to clarify its mechanism at fee molecular level. Firstly, structure and size of solvent clusters predominantly formed in various alcohol-water mixtures have been investigated by using X-ray and neutron scattering techniques. It has been shown that the larger the hydrophobic group of alcohols, the more the tetrahedral-like structure of water is disrupted at low alcohol concentration, result in that alcohol molecules easily aggregate to form solvent clusters. In particular, the results from small-angel neutron scattering experiments have shown that fluoroalcohols of trifluoroethanol(TFE) and hexafluoroisopropanol(HFIP) significantly form solvent clusters in their aqueous solutions. These findings, together with the fact that the fluoroalcohols more strongly induce protein folding than aliphatic alcohols, such as ethanol(EtOH) and 2-propanol(2-PrOH), suggest the relation between cluster formation and protein folding.
Solvation behavior of 1,4-pentanediol molecule, which involves a hydrophobic hydrocarbon chain and two hydrophilic hydroxyl groups, as a model of peptide molecule in various alcohol-water mixtures has been investigated by using infrared spectroscopy and NMR. The results have suggested that addition of ethanol and 2-propanol into aqueous 1,4-pentanediol solution induces to dehydration from the hydroxyl groups of 1,4-pentanediol molecule, whereas TFE and HFIP strongly interact to the hydrocarbon chain. It has also been shown that the hydrophobic interaction between alcohol molecule and the hydrocarbon chain of 1,4-pentanediol molecule is more stronger in the sequence of HFIP>TFE>EtOH【approximately equal】2-PrOH. This sequence is in agreement with that for the effect of alcohol on protein folding. The present investigation has suggested that interaction between alcohol clusters and protein molecule significantly contributes to protein folding.
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Report
(3 results)
Research Products
(37 results)
