Breakthrough model of recombinant human-like collagen in immobilized metal affinity chromatography.

The adsorption of recombinant human-like collagen by metal chelate media was investigated in a batch reactor and in a fixed-bed column. The adsorption equilibrium and kinetics had been studied by batch adsorption experiments. Equilibrium parameters and protein diffusivities were estimated by matching the models with the experimental data. Using the parameters of equilibrium and kinetics, various models, such as axial diffusion model, linear driving force model, and constant pattern model, were used to simulate the breakthrough curves on the columns. As a result, the most suitable isotherm was the Langmuir-Freundlich model, and the ionic strength had no effect on the adsorption capacity of chelate media. In addition, the pore diffusion model fitted very well to the kinetic data. The pore diffusivities decreased with increasing the initial protein concentration, however had little change with the ionic strength. The results also indicated that the models predict breakthrough curves reasonably well to the experimental data, especially at low initial protein concentration (0.3 mg ml(-1)) and low flow rate (34 cm h(-1)). By the results, we optimized the experimental conditions of a chromatographic process using immobilized metal affinity chromatography to purify recombinant human-like collagen.