<> "The repository administrator has not yet configured an RDF license."^^ . <> . . . "Direct UV Raman monitoring of 310-helix and π-bulge premelting during α-helix unfolding"^^ . "We used UV resonance Raman (UVRR) spectroscopy exciting at ∼200 nm within the peptide bond π→π* transitions to selectively study the amide vibrations of peptide bonds during α-helix melting. The dependence of the amide frequencies on their Ψ Ramachandran angles and hydrogen bonding enables us, for the first time, to experimentally determine the temperature dependence of the peptide bond Ψ Ramachandran angle population distribution of a 21-residue mainly alanine peptide. These Ψ distributions allow us to easily discriminate between α-helix, 310-helix and α-helix/bulge conformations, obtain their individual melting curves, and estimate the corresponding Zimm and Bragg parameters. A striking finding is that α-helix melting is more cooperative and shows a higher melting temperature than previously erroneously observed. These Ψ distributions also enable the experimental determination of the Gibbs free energy landscape along the Ψ reaction coordinate, which further allows us to estimate the free energy barriers along the AP melting pathway. These results will serve as a benchmark for the numerous untested theoretical studies of protein and peptide folding. © 2006 American Chemical Society."^^ . "2006-10-25" . . "128" . "42" . . "Journal of the American Chemical Society"^^ . . . "00027863" . . . . . . . . . . "SA"^^ . "Asher"^^ . "SA Asher"^^ . . "AV"^^ . "Mikhonin"^^ . "AV Mikhonin"^^ . . . . . . "Direct UV Raman monitoring of 310-helix and π-bulge premelting during α-helix unfolding (Plain Text)"^^ . . . "licence.txt"^^ . . . "Direct UV Raman monitoring of 310-helix and π-bulge premelting during α-helix unfolding (Other)"^^ . . . . . . "indexcodes.txt"^^ . . "HTML Summary of #17211 \n\nDirect UV Raman monitoring of 3<inf>10</inf>-helix and π-bulge premelting during α-helix unfolding\n\n" . "text/html" . .