This is like the species with mass conservation model, but with the following difference:
* only one species is allowed
* the concentration parameters are in micromolar units, and utilize the extinction coefficient data of the experiments.
* the parameter box follows the same form as the interacting species models:
As can be seen from the redundancy with other models, this is thought as a more convenient model to fit the data from an individual protein species, preceding the analysis of the mixture.