Effects of Immobilized Metal Ion on Retention Behaviors of Proteins in Metal Chelate Affinity Chromatography |
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| Authors: | Rong Li Yan Wang Guo‐Liang Chen Mei‐Shi Xiao‐Gang Wang Jian‐Bin Zheng Bin Chen |
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| Institution: | 1. School of Chemical Engineering, Northwest University, Xi'an 710069, P. R. China;2. Institute of Analytical Science, Northwest University, Xi'an 710069, P. R. China |
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| Abstract: | The chromatographic behaviors of proteins on iminodiacetic acid (IDA) column with and without immobilized metal ion were examined in detail. Comparing the effects of pI, solution pH, and salt concentration on retention of proteins in cation‐exchange chromatography (CEC) and metal chelate affinity chromatography (MCAC), the retention mechanism of proteins was investigated in MCAC. By aid of observing the retention characteristics of proteins on naked IDA and metal chelate columns in high concentration salt‐out salt solution, the hydrophobic interaction in MCAC and the influence of metal ion on it were proved. In terms of the comparison of the thermodynamics of proteins in CEC and MCAC, the thermostability, the conformational change entropy Δ(ΔS0) and enthalpy Δ(ΔH0), compensation temperature β, the driving force and caloritic effect of proteins in MCAC were discussed. The identity of retention mechanism at protein thermal denaturation in CEC and MCAC was demonstrated by using the compensation relationship between ΔH0 and ΔS0. |
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| Keywords: | Metal chelate affinity chromatography Cation‐exchange chromatography Protein Retention mechanism Chromatographic thermodynamics |
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