title: NMR studies on thermal stability of α-helix conformation of melittin in pure ethanol and ethanol-water mixture solvents.
abstract: Thermal stability of the α-helix conformation of melittin in pure ethanol and ethanol-water mixture solvents has been investigated by using NMR spectroscopy. With increase in water concentration of the mixture solvents (from 0 wt% to ~71.5 wt%) as well as temperature (from room temperature to 60 °C), the intramolecular hydrogen bonds formed in melittin are destabilized and the α-helix is partially uncoiled. Further, the hydrogen bonds are found to be more thermally stable in pure ethanol than in pure methanol, suggesting that their stability is enhanced with increase in the size of the alkyl groups of alcohol molecules.
authors.affiliation: Center for Advanced Instrumental Analysis, Kyushu University, Kasuga, Japan. yoshi@mm.kyushu-u.ac.jp
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Miura
mesh_terms: D000595:Amino Acid Sequence; D000431:Ethanol / Q000737:chemistry*; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D008555:Melitten / Q000737:chemistry*; D008969:Molecular Sequence Data; D055550:Protein Stability; D017433:Protein Structure, Secondary; D012997:Solvents / Q000737:chemistry*; D013696:Temperature; D014867:Water / Q000737:chemistry*
chemical_list: D012997:Solvents; D014867:Water; D008555:Melitten; D000431:Ethanol