Engineering HDR Seminar Series 3, 2013: Development of Dual Functions Negative Chromatography Adsorbent for the Purification of Hepatitis B Core Antigen from Escherichia coli Homogenate

Mr Micky Lee Fu Xiang, postgraduate student from Chem Eng

Date: 2013-02-04
Time: 10:00 to 11:00
Venue: Engineering Meeting Room 1, 5-4-22


Recombinant Hepatitis B core antigen (HBcAg) has been demonstrated as potential reagent for diagnostic kit and vaccine to detect and to prevent Hepatitis B virus infection. The advances in genetic engineering have led to the improvement of protein expression level. Recent report showed that HBcAg expressed in Escherichia coli was about 30% of the total host cell protein. Hence, it has created a bottleneck in the downstream processing as the conventional protein purification method such as direct capture chromatography has limitation in protein capture capacity. In order to keep track with the increment in protein production, negative chromatography is proposed to levelling this bottleneck problem. Therefore, the main objective of this project is to develop a suitable adsorbent for the negative chromatography for the purification of HBcAg from Escherichia coli homogenate. A dual functions polymer grafted cellulose adsorbent with size exclusion and ion exchange properties is used as negative chromatography adsorbent in this study. The fabricated adsorbent is able to exclude the larger HBcAg protein and separate it from other smaller host proteins through negative chromatography. Therefore, poly(ethylene glycol) methyl ether methacrylate layer (PEGMA) and diethylaminoethyl methacrylate layer (DEAEMA) will be grafted by atom transfer radical polymerization (ATRP) on the cellulose adsorbent as size exclusion layer and ion exchange layer, respectively. The effect of grafting density of the polymers on the partition of the proteins through the polymer layer will be studied. The chain length of the grafted polymers will be studied to provide optimum size exclusion of HBcAg and optimum adsorption of host protein on the cellulose adsorbent. The performance of the adsorbent in packed bed of negative chromatography for the purification of HBcAg will be evaluated. The development of the adsorbents is expected to be a solution to unblock the bottleneck problems of downstream process of highly expressed recombinant HBcAg.

About the Speaker

Mr Micky Lee Fu Xiang graduated from University Malaysia Sabah (UMS) with a Bachelor of Chemical Engineering (Honours) in year 2011. He joined Monash University for postgraduate studies in year 2012 under the supervision of Prof. Tey Beng Ti and co-supervision of Assoc. Prof. Chan Eng Seng. His research in Monash University is focused on development of dual functions negative chromatography adsorbent for the purification of Hepatitis B core antigen from Escherichia coli homogenate.