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Titolo:
DIPOLE POTENTIAL DROP ON THE MEMBRANE SOL UTION BOUNDARY DUE TO ADSORPTION OF STYRYL DYES RH-421, RH-237 AND RH-160
Autore:
MALKOV DY; SOKOLOV VS;
Indirizzi:
RUSSIAN ACAD SCI,AN FRUMKIN ELECTROCHEM INST MOSCOW RUSSIA
Titolo Testata:
Biologiceskie membrany
fascicolo: 6, volume: 12, anno: 1995,
pagine: 652 - 663
SICI:
0233-4755(1995)12:6<652:DPDOTM>2.0.ZU;2-O
Fonte:
ISI
Lingua:
RUS
Soggetto:
LIPID BILAYER MEMBRANES; CHARGE-SHIFT PROBES; ELECTROCHROMIC MECHANISM; ION-TRANSPORT; PHLORETIN; BINDING; TRANSLOCATION; NA,K-PUMP;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
29
Recensione:
Indirizzi per estratti:
Citazione:
D.Y. Malkov e V.S. Sokolov, "DIPOLE POTENTIAL DROP ON THE MEMBRANE SOL UTION BOUNDARY DUE TO ADSORPTION OF STYRYL DYES RH-421, RH-237 AND RH-160", Biologiceskie membrany, 12(6), 1995, pp. 652-663

Abstract

Potential drops at the boundary of the bilayer lipid membrane (BLM) due to adsorption of the potential-sensitive dyes (RH-421, RH-237 and RH-160) were studied. The magnitudes of these drops were determined by different experimental methods. Potential distribution with respect tothe plane of the adsorption of hydrophobic ions was evaluated from the kinetic parameters of the transport of hydrophobic ions (tetraphenylborate and dipicrylamine) across the membrane (current relaxation method). The changes in boundary potential (BP) difference on the membranewere monitored by the method based on the intramembrane field compensation (IFC) using the second harmonic of the capacitive current. The changes in the zeta-potential in liposomes were measured by correlationspectroscopy. The adsorption of the dyes led to a considerable changein the rate constant of the translocation of hydrophobic ions throughthe BLM and did not affect their partition coefficient between membrane and water. This indicates that the dye-induced potential drop in the membrane is located deeper than the plane of the adsorption of hydrophobic ions. The values of the BP difference measured by the IFC method upon the dye addition to the solution on one side of the membrane were less than those obtained by the current relaxation method (symmetrical addition). Proceeding from the results, we proposed that moleculesof the compounds studied penetrated through the lipid bilayers. The values of the zeta-potential did not. change upon the dye adsorption; hence, we suggested that the dye molecules are adsorbed in the electroneutral form. It was shown that the adsorption of RH dyes resulted in the dipole potential drop, positive in the hydrophobic region of the BLM. We also estimated the influence of the electric field of dye dipolelayer on a dipole situated in the same layer and on ions in the interior of such a protein as Na+/K+-ATPase.

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Documento generato il 19/09/20 alle ore 06:48:26