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On the Hydration State of Amino Acids and Their Derivatives at Different Ionization States : A Comparative Multinuclear NMR and Crystallographic Investigation
Joint Authors
Tzakos, Andreas G.
Pappas, Charalampos G.
Gerothanassis, Ioannis P.
Source
Issue
Vol. 2012, Issue 2012 (31 Dec. 2012), pp.1-11, 11 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2012-05-14
Country of Publication
Egypt
No. of Pages
11
Main Subjects
Abstract EN
2D, 13C, 14N, and 17O NMR and crystallographic data from the literature were critically evaluated in order to provide a coherent hydration model of amino acids and selected derivatives at different ionization states.
17O shielding variations, longitudinal relaxation times (T1) of 2D and 13C and line widths (Δν1/2) of 14N and 17O, may be interpreted with the hypothesis that the cationic form of amino acids is more hydrated by 1 to 3 molecules of water than the zwitterionic form.
Similar behaviour was also observed for N-acetylated derivatives of amino acids.
An exhaustive search in crystal structure databases demonstrates the importance of six-membered hydrogen-bonded conjugated rings of both oxygens of the α-carboxylate group with a molecule of water in the vicinity.
This type of hydrogen bond mode is absent in the case of the carboxylic groups.
Moreover, a considerable number of structures was identified with the propensity to form intramolecular hydrogen bond both in the carboxylic acid (NH⋯O=C) and in the carboxylate (NH⋯O−) ionization state.
In the presence of bound molecules of water this interaction is significantly reduced in the case of the carboxylate group whereas it is statistically negligible in the carboxylic group.
American Psychological Association (APA)
Pappas, Charalampos G.& Tzakos, Andreas G.& Gerothanassis, Ioannis P.. 2012. On the Hydration State of Amino Acids and Their Derivatives at Different Ionization States : A Comparative Multinuclear NMR and Crystallographic Investigation. Journal of Amino Acids،Vol. 2012, no. 2012, pp.1-11.
https://search.emarefa.net/detail/BIM-481233
Modern Language Association (MLA)
Pappas, Charalampos G.…[et al.]. On the Hydration State of Amino Acids and Their Derivatives at Different Ionization States : A Comparative Multinuclear NMR and Crystallographic Investigation. Journal of Amino Acids No. 2012 (2012), pp.1-11.
https://search.emarefa.net/detail/BIM-481233
American Medical Association (AMA)
Pappas, Charalampos G.& Tzakos, Andreas G.& Gerothanassis, Ioannis P.. On the Hydration State of Amino Acids and Their Derivatives at Different Ionization States : A Comparative Multinuclear NMR and Crystallographic Investigation. Journal of Amino Acids. 2012. Vol. 2012, no. 2012, pp.1-11.
https://search.emarefa.net/detail/BIM-481233
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-481233