| Autor: |
Upadhyayula S; Department of Bioengineering, University of California, Riverside, California 92521, United States., Bao D, Millare B, Sylvia SS, Habib KM, Ashraf K, Ferreira A, Bishop S, Bonderer R, Baqai S, Jing X, Penchev M, Ozkan M, Ozkan CS, Lake RK, Vullev VI |
| Jazyk: |
angličtina |
| Zdroj: |
The journal of physical chemistry. B [J Phys Chem B] 2011 Aug 04; Vol. 115 (30), pp. 9473-90. Date of Electronic Publication: 2011 Jul 08. |
| DOI: |
10.1021/jp2045383 |
| Abstrakt: |
Electrostatic properties of proteins are crucial for their functionality. Carboxyamides are small polar groups that, as peptide bonds, are principal structural components of proteins that govern their electrostatic properties. We investigated the medium dependence of the molar polarization and of the permanent dipole moments of amides with different state of alkylation. The experimentally measured and theoretically calculated dipole moments manifested a solvent dependence that increased with the increase in the media polarity. We ascribed the observed enhancement of the amide polarization to the reaction fields in the solvated cavities. Chloroform, for example, caused about a 25% increase in the amide dipole moments determined for vacuum, as the experimental and theoretical results demonstrated. Another chlorinated solvent, 1,1,2,2-tetrachloroethane, however, caused an "abnormal" increase in the experimentally measured amide dipoles, which the theoretical approaches we used could not readily quantify. We showed and discussed alternatives for addressing such discrepancies between theory and experiment. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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