Classification and localization of hemoglobin binding sites on the red blood cell membrane.
The binding of hemoglobin to the red cell membrane was characterized over a wide range of free hemoglobin concentrations by measurement of membrane bound and supernatant hemoglobin. Scatchard analysis of the binding data revealed two classes of sites: high affinity sites with a binding constant of 1 X 10(8) M-1 and 1.2 X 10(6) sites per cell, and a second, low affinity class of sites with a binding constant of 6 X 10(6)M-1 and 6 X 10(6) sites per cell. The low affinity sites are shown to be nonspecific and appear to be a result of the ghost preparation. The high affinity sites are shown to be specific to the inner surface of the red cell membrane. The competition of hemoglobin and glyceraldehyde-3-phosphate dehydrogenase suggests band III proteins as a potential binding site for hemoglobin.
D001665:Binding Sites; D004910:Erythrocyte Membrane / Q000648:ultrastructure*; D004912:Erythrocytes / Q000648:ultrastructure*; D005634:Fructose-Bisphosphate Aldolase; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D006454:Hemoglobins; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D011485:Protein Binding; D013050:Spectrometry, Fluorescence
D006454:Hemoglobins; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D005634:Fructose-Bisphosphate Aldolase