Process intensification of immobilized metal affinity chromatography with longitudinal and oscillatory transverse electric fields

We have integrated immobilized metal affinity chromatography (IMAC) with preparative electrochromatography to study the intensification effects of electric field (EF) on the IMAC process for protein binding and purification. A seven-compartment chromatographic column with longitudinal (L), oscillatory transverse (T) or two-dimensional (2D) electric fields was designed for the studies. IMAC experiments were conducted to assess the performance of the electrochromatography and to optimize protein adsorption conditions. Compared with the dynamic binding capacity (DBC) in normal mode without an EF (nEF), the DBC for bovine serum albumin increased by 23%, 67% and 130% in modes of L-, T- and 2D-EF, respectively. This confirmed that EF had great contribution to the intensification of IMAC process. Such phenomenon of intensification caused by EF was also of universality and unrelated to metal ions immobilized on the adsorbents. In the purification of alcohol dehydrogenase (ADH) from clarified yeast extract, the loading volume in the mode of 2D-EF could be increased to twice that in the mode of nEF. At the double feed loading condition, the application of 2D-EF still led to significant improvement in the purification performance, such as the increase of activity yield from 65.4% to 84.6%, specific activity from 15.9 U/mg to 17.5 U/mg, and purification factor from 6.36 to 7.04. Therefore, the application of 2D-EF could strikingly intensify the IMAC performance and the IMAC in 2D-EF mode exhibited a good potential in protein purification from complex feedstocks.

Figure optionsDownload as PowerPoint slideResearch highlights▶ Immobilized metal affinity chromatography was integrated with two-dimensionalelectric fields (2D-EF) for the intensification of protein purification process. ▶ The dynamic binding capacity of protein could be 2.3 times increased with the 2D-EF. ▶ In the purification of alcohol dehydrogenase, the loading volume in the mode of 2D-EF could be twice increased. ▶ The application of 2D-EF led to significant improvement in the purification performance at the double feed loading condition.