Simulation studies of self-associating systems; discrimination between specific and isodesmic associations

The possibilities of discriminating between definite and indefinite (isodesmic) modes of self-association are explored by fitting the different models to stimulated data, using non-linear least-squares curve-fitting to determine the fitting parameters for real and impostor models. It was found that over an extensive range of values for the equilibrium constant of a non-ideal isodesmic generating model, only a non-ideal monomer-dimer-tetramer-octamer was a successful impostor model. Some criteria for rejecting inappropriate models are discussed.