A. IFTIME, IOANA PLAJER, CONSTANTA GANEA

Department of Biophysics, “Carol Davila” University of Medicine and Pharmaceutics, 8, Eroii Sanitari Blvd, 050474 Bucharest, Romania

Abstract. The effects of the lyotropic anion nitrite on the transient and stationary photocurrents of bacteriorhodopsin (bR) adsorbed to planar lipid bilayers were followed up at different nitrite concentrations. On raising the nitrite concentrations, both transient and stationary photocurrents increased and, at the same time, the kinetics of the bR photocycle was modified, showing an acceleration at nitrite concentrations below 100 mM and a slowing down above this value. The effects of nitrite were explained taking into account the slightly chaotropic character of this anion and the possible interaction both with the dipole potential of the membrane and/or with the charged groups of the protein.

Author’s e-mail: ad_if@yahoo.co.uk

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