Premium
SPECTROSCOPIC PROPERTIES OF THE POTENTIOMETRIC PROBE MEROCYANINE‐540 IN SOLUTIONS AND IN LIPOSOMES
Author(s) -
Ehrenberg Benjamin,
Pevzner Eliyahu
Publication year - 1993
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1993.tb02280.x
Subject(s) - chemistry , raman spectroscopy , potentiometric titration , analytical chemistry (journal) , valinomycin , liposome , merocyanine , membrane , binding constant , fluorescence , absorption spectroscopy , photochemistry , absorption (acoustics) , chromatography , materials science , binding site , electrode , biochemistry , physics , quantum mechanics , photochromism , optics , composite material
Absorption, fluorescence and resonance Raman spectra of the membrane dye merocyanine‐540 (MC540) were measured. The aggregation of the dye, its binding to lipid membranes and its response to crossmembrane electric potential differences were studied. The dye was found to aggregate even at micromolar concentrations in water, but not in organic solvents. The dimerization constant was evaluated by spectroscopic techniques. The binding constant to liposomes was estimated by a spectroscopic titration method. Resonance Raman spectra of MC540 were measured for the first time. Distinct changes were observed in the vibrational spectrum upon the generation of a valinomycin‐induced K + diffusion potential (Nernst potential) on liposomes. The ratio of Raman band intensities, which was found to be related to the membrane potential, can be used to evaluate the absolute value of the electric potential.