Modulation of valinomycin conductance by palmitic acid in planar lipid bilayers evidences fatty acid flip-flop (2004)
- Authors:
- USP affiliated authors: CURI, RUI - ICB ; ARAUJO FILHO, JOAQUIM PROCOPIO DE - ICB
- Unidade: ICB
- Assunto: FISIOLOGIA
- Language: Português
- Abstract: Objetivo: The aim of the present work is to evaluate the steady-state and temporal evolution of fatty acid distribution in neutral lipid bilayer membranes (DPhPC) by monitoring the valinomycin-induced membrane conductance in the presence of potassium. Fatty acids are added to the aqueous medium whence they partition into the membrane phase. Métodos e Resultados: Addition of palmitic acid (PA) to the medium increases the membrane conductance to the valinomycin-potassium complex indicating the generation of a negative surface potential (SP) most probably due to the insertion into the membrane of negatively charged residues. Upon insertion of palmitic acid (PA) into the membrane, a negative SP is generated by the palmitate anions adsorbed, which increases potassium conductance by locally rising potassium concentration. Addition of PA to one of the membrane bathing solution (CIS) rises membrane conductance about 5 times, which amounts to a SP of - 39.1 ± 11.4 mV and a surface charge density of 6.2 ± 2.8 mC/m2 (n = 8). Acidification of the opposite bathing solution (TRANS) markedly rectifies the current-voltage characteristics, although the reversal potential remains approximately 0 mV. Such findings are compatible with the protonation of fatty acid residues in TRANS, generating a SP asymmetry across the membrane, which causes the potassium conductance rectification in the absence of potassium electrochemical gradients. Conclusões: PA adsorbs to neutralmembranes, generating negative surface charges, and rapidly equilibrates between the two leaflets. This effect may have a role in the modulation of membrane potentials of living cells
- Imprenta:
- Publisher place: Águas de Lindóia
- Date published: 2004
- Source:
- Título: Resumos
- Conference titles: Reunião Anual da Federação de Sociedades de Biologia Experimental, FeSBE
-
ABNT
ABDULKADER, Fernando et al. Modulation of valinomycin conductance by palmitic acid in planar lipid bilayers evidences fatty acid flip-flop. 2004, Anais.. Águas de Lindóia: Instituto de Ciências Biomédicas, Universidade de São Paulo, 2004. . Acesso em: 09 abr. 2026. -
APA
Abdulkader, F., Brunaldi, K., Miranda, M. A., Curi, R., & Procopio, J. (2004). Modulation of valinomycin conductance by palmitic acid in planar lipid bilayers evidences fatty acid flip-flop. In Resumos. Águas de Lindóia: Instituto de Ciências Biomédicas, Universidade de São Paulo. -
NLM
Abdulkader F, Brunaldi K, Miranda MA, Curi R, Procopio J. Modulation of valinomycin conductance by palmitic acid in planar lipid bilayers evidences fatty acid flip-flop. Resumos. 2004 ;[citado 2026 abr. 09 ] -
Vancouver
Abdulkader F, Brunaldi K, Miranda MA, Curi R, Procopio J. Modulation of valinomycin conductance by palmitic acid in planar lipid bilayers evidences fatty acid flip-flop. Resumos. 2004 ;[citado 2026 abr. 09 ] - Glutamine and glutamate as vital metabolites
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