Biochemistry, 5(1):365-385, 1966. Paper abstract bibtex
Models for subunit interactions are examined by means of interpreting ligand saturation curves. Equations are derived to indicate the effect of variables such as the strength of binding of the ligand, the geo- metrical arrangement of subunits, the strength of inter- action between subunits, the energy of the conforma- tion change, and the effect of nonidentical subunits. Rapid methods, i.e., equations and nomograms, are developed to fit theoretical curves to experimental data with a minimum of parameters. Applying these pro- cedures to the binding of oxygen by hemoglobin as an illustrative example, it is seen that a number of simple models can represent the published data accurately. In general it appears that unique mechanisms cannot be established from ligand saturation curves by them- selves, but the mathematical analysis of the curves indi- cates possible sources of additional information to make such distinctions possible.