Phenylalanine interaction with lipid monolayers at different pHs.
The influence of Phe on the surface pressure of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) monolayers at the air-water interface was studied at different initial surface pressures (26 and 40 mN/m) and two pHs (5.0 and 7.3) at constant temperature (20 °C). Changes produced by the aminoacid added to the subphase on the surface pressure and on the dipole potential of lipid monolayers were measured at a fixed area. Compressibility properties of the monolayers at different pHs were studied by (π-A) isotherms. The results suggest that Phe intercalates into a DPPC film at the air-water interface at pH 5 and forms a different arrangement at pH 7.3. The possible relevance of these results of the effect of Phe in physiological conditions is discussed.
Laboratorio de Biointerfases y Sistemas Biomiméticos, Laboratorios Centrales, CITSE-UNSE, Santiago del Estero, Argentina.
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Cutró
Laboratorio de Biointerfases y Sistemas Biomiméticos, Laboratorios Centrales, CITSE-UNSE, Santiago del Estero, Argentina.
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Hollmann
Laboratorio de Biointerfases y Sistemas Biomiméticos, Laboratorios Centrales, CITSE-UNSE, Santiago del Estero, Argentina.
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Cejas
Laboratorio de Biointerfases y Sistemas Biomiméticos, Laboratorios Centrales, CITSE-UNSE, Santiago del Estero, Argentina.
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Maturana
Laboratorio de Biointerfases y Sistemas Biomiméticos, Laboratorios Centrales, CITSE-UNSE, Santiago del Estero, Argentina. Electronic address: disalvoanibal@yahoo.com.ar.
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Disalvo
Laboratorio de Biointerfases y Sistemas Biomiméticos, Laboratorios Centrales, CITSE-UNSE, Santiago del Estero, Argentina.
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Frías
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry; D000465:Algorithms; D006863:Hydrogen-Ion Concentration; D008055:Lipids / Q000737:chemistry*; D008567:Membranes, Artificial; D010649:Phenylalanine / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature; D013816:Thermodynamics
D008055:Lipids; D008567:Membranes, Artificial; D015060:1,2-Dipalmitoylphosphatidylcholine; D010649:Phenylalanine
DPPC; Dipole potential-pH; Lipid monolayers; Phenylalanine; Surface pressure