A quaternary amine cryogel column for chromatographic capture of l-asparaginase

Abstract

L-asparaginase is a therapeutic enzyme used in therapies of acute lymphoblastic leukemia. Its purification conventionally uses several unit operations, and usual protocols lead to low yields and extensive processing times, which reduce productivity and increases process costs. In this study, we produced a supermacroporous cryogel activated with polyethyleneimine, followed by quaternization with epichlorohydrin resulting in a quaternary ammonium anion-exchanger. The anionic cryogel had a ligand density of 121.6 mmol/L and the HETP ranged from 0.18 to 0.27 cm. The activated cryogel was applied to capture L-asparaginase from filtered broth. Yield and purification fold (PF) were optimized using the response-surface methodology, resulting in optimum values of 56 % and 7.6, respectively. The effect of flow velocity over PF was also analyzed, and the results showed that PF had an average value of 8.5 and did not vary with the fluid velocity, confirming the convective mass transfer property of the activated cryogel. The results showed that the activated cryogel shows advantages in using unclarified broth without pretreatment and works at a high flow rate with the perspective of reducing unit production cost.