A cooperative model for ligand binding to biological macromolecules as applied to oxygen carriers.
This paper presents a model describing the thermodynamics of cooperative ligand binding to multimeric biological macromolecules and integrating some of the features of the two-state and induced-fit models. The protein is taken to be partitioned into a number of noninteracting functional constellations, each one existing in two possible quaternary conformations. Furthermore, the model postulates that a functional constellation is organized in several subsets of sites (called cooperons), in which subunits interact according to an induced-fit mechanism. In the present version the number of subunits forming a cooperon has been limited to two and the total number of parameters used for fitting experimental data is four, all having a precise physical meaning. Although the present application is limited to oxygen-carrying proteins (hemoglobins, hemocyanins, erythrocruorins), the model appears suitable to describe other biological macromolecules with functional interactions.
M
M
Brunori
M
M
Coletta
E
E
Di Cera
D000818:Animals; D004902:Erythrocruorins / Q000378:metabolism; D006433:Hemocyanins / Q000378:metabolism; D006454:Hemoglobins / Q000378:metabolism; D007700:Kinetics; D008024:Ligands; D046911:Macromolecular Substances; D008433:Mathematics; D008954:Models, Biological; D010100:Oxygen / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*
D004902:Erythrocruorins; D006454:Hemoglobins; D008024:Ligands; D046911:Macromolecular Substances; D011506:Proteins; D006433:Hemocyanins; D010100:Oxygen