Y. Sato, T. Chiba, Y. Suzuki
Sep 25, 1985
Citations
0
Influential Citations
5
Citations
Quality indicators
Journal
Chemical & pharmaceutical bulletin
Abstract
The interaction between eosin 5-isothiocyanate (EITC) and human erythrocyte ghosts has been studied by means of fluorescence and absorption difference spectroscopy. The fluorescence quenching data of the ghost-EITC system showed a biphasic change. EITC molecules bound to band 3 proteins and adsorbed on ghost membranes are responsible for this biphasic change. Binding of EITC molecules to the ghosts leads to a redshift and hypochromism in the visible region. Consequently, the difference spectrum shows a positive peak and two negative ones at 540, 517, and 483 nm from the longer wavelength side. The intensities of these peaks change heterogeneously under various conditions, reflecting the contributions of xanthene and phenyl chromophores bound to band 3. It was considered that the conformational structure of EITC binding sites is sensitive to temperature, showing a transition at about 30°C. The reactivity of EITC molecules with band 3 at temperatures below 30°C is different from that above 30°C. It is inferred that the EITC binding sites on band 3 are identical with the modifier sites.