Interaction of Phenylalanine with DPPC Model Membranes: More Than a Hydrophobic Interaction
| Autor: | Antonio Sebastián Rosa, María de los Ángeles Frías, Edgardo Anibal Disalvo, Andrea Carmen Cutró |
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| Rok vydání: | 2015 |
| Předmět: |
Models
Molecular 1 2-Dipalmitoylphosphatidylcholine Hydrogen bond Chemistry Entropy Phenylalanine Water Hydrogen Bonding Surfaces Coatings and Films Gibbs free energy Hydrophobic effect Dissociation constant chemistry.chemical_compound Crystallography symbols.namesake Membrane Materials Chemistry Zeta potential symbols Organic chemistry Moiety Carboxylate Physical and Theoretical Chemistry Hydrophobic and Hydrophilic Interactions |
| Zdroj: | The Journal of Physical Chemistry B. 119:15844-15847 |
| ISSN: | 1520-5207 1520-6106 |
| Popis: | The negative free energy previously reported is explained by the stabilization of a PC-Phe (phosphocholine-phenylalanine) complex in the presence of water shown by the decrease in the symmetric stretching frequency of the phosphate group of the lipid (PO2(-)). An entropic contribution due to the disruption of the water network around the phenyl and in the membrane defect may be invoked. The dipole potential decrease is explained by the orientation of the carboxylate opposing to the CO of the lipids with oxygen moiety toward the low hydrated hydrocarbon core. The symmetric bending frequency of NH3(+) group of Phe, decreases in 5.2 cm(-1) in relation to water congruent with zeta potential shift to positive values. The Phe to DPPC dissociation constant is Kd = 2.23 ± 0.09 mM, from which the free energy change is about -4.54 kcal/mol at 25 °C. This may be due to hydrophobic contributions and two hydrogen bonds. |
| Databáze: | OpenAIRE |
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