Conformations and properties of the L‐tryptophyl‐containing peptides in solution,depending on the pH—Theoretical study vs. experiments |
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Authors: | Bojidarka B. Ivanova Michael Spiteller |
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Affiliation: | 1. Faculty of Chemistry, Sofia University St. Kl. Ohridski, 1, J. Bourchier Blvd., Sofia 1164, Bulgaria;2. Institut für Umweltforschung, Universit?t Dortmund, Otto‐Hahn‐Strasse 6, Dortmund 44221, Germany |
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Abstract: | The conformational preference and electronic properties of three L ‐tryptophyl‐containing dipeptides, i.e., glycyl‐L ‐tryptophane (H‐Gly‐Trp‐OH), L ‐alanyl‐L ‐tryptophane (H‐Ala‐Trp‐OH), and L ‐methionyl‐L ‐tryptophane (L ‐Met‐Trp‐OH) in solution depending on the pH of the media are studied both theoretically and experimentally. The effect of the protonation of the COO? and deprotonation of the NH as well as the alkaline hydrolysis of the amide fragment in a strong basic media on the electronic spectra are discussed. Ab initio and density functional theory (DFT) methods as well as the time‐dependent DFT (TD‐DFT) method as a function of the basis set are performed with a view to obtain the geometry and electronic properties of all of the species as well as the intermediate, obtained in the alkaline hydrolysis mechanism. © 2010 Wiley Periodicals, Inc. Biopolymers 93: 727–734, 2010. This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com |
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Keywords: | glycyl‐L‐tryptophane L‐alanyl‐L‐tryptophane L‐methionyl‐L‐tryptophane conformations TD‐DFT electronic absorption spectral simulations UV‐vis spectroscopy |
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