Analytic models for nonlinear curve-fitting of forward-rate binding data, with applications to hemoglobin.
The experimental procedure of Perrella et al. (1983, J. Biol. Chem. 258, 4511-4517) can reveal most of the intermediate ligation states of hemoglobin either at equilibrium or in a kinetic reaction. In this paper, a model of stepwise ligand binding, under conditions of negligible reverse reaction, is derived with particular attention to hemoglobin. The model leads to a two-phase procedure. First, the ratios of the forward rates are determined by fitting the model to normalized concentrations vs. saturation. Second (optionally), an auxiliary relation is used to deduce the scale factor for the rates that make the model consistent with time information if such is available. The procedure has been applied to hemoglobin binding of the ligands carbon monoxide (this paper) and ferricyanide (manuscript in preparation).
Shrager
R I
RI
Division of Computer Research and Technology, National Institutes of Health, Bethesda, MD 20892.
D000465:Algorithms; D002248:Carbon Monoxide / Q000493:pharmacokinetics; D006454:Hemoglobins / Q000502:physiology*; D007700:Kinetics; D008962:Models, Theoretical; D012984:Software
D006454:Hemoglobins; D002248:Carbon Monoxide