Interaction of hemoglobin with red blood cell membranes as shown by a fluorescent chromophore

Abstract

Hb quenching of the fluorescence intensity of 12-(9-anthroyl)stearic acid (AS) embedded in the red blood cell [human] membrane occurs through an energy transfer mechanism and can be used to measure the binding of Hb to the membrane. The binding of Hb to red cell membranes was reversible and electrostatic in nature. Using a theory of energy transfer based on Forster formulation, the quantitative data for the binding were derived. The number of binding sites was 1.4 .+-. 0.2 .times. 106 molecules per cell and the binding constant was 0.85 .times. 108 M-1.