Characterization of superporous cellulose matrix for high‐throughput adsorptive purification of lysozyme

Abstract

Protein purification essentially requires macroporous adsorbents matrices, which can provide high efficiency in packed bed and expanded bed (EB) even at high flow rates on account of reduced pore diffusion resistance resulting from finite intraparticle flow in the superpores. Rigid spherical superporous adsorbent beads with high carboxyl group density were prepared by crosslinking of cellulose. The matrix (diameter: 100-300 μm, mean pore size: 1-3 μm, pore volume: 57-59%, and bulk density: ∼1,438 kg/m3) could be used in packed bed as well as EB for purification of various biomolecules. Attempts were made to use indigenously developed rigid, superporous crosslinked cellulose adsorbent for high-throughput purification of lysozyme from chicken egg white's extract. A typical adsorption isotherm for lysozyme in crude was well correlated with the Langmuir isotherm model. Two maxima of binding capacity on celbeads bearing carboxymethyl (celbeads-CM) group for lysozyme were observed at pH 4.5 and 7.5. Uptake kinetics showed that the diffusivity of lysozyme was 100 times higher than conventional matrices. Such superporous matrix can be used for high-throughput purification of proteins from crude feedstocks and is reflected in leveling off of height equivalent to theoretical plate vs. flow curve after threshold velocity. Optimization of binding and elution conditions resulted in overall purification of lysozyme in a high yield and purity of 98.22 and 98.8%, respectively, with purification factor of 51.54 in a single step. The overall productivity (14.21 kg/m3 h) and specific activity (2.2×10(5) U/mg) were higher than that obtained with traditional particulate resins.

Catalytic metallodendrimers grafted on mesoporous polymethacrylate beads for the regioselective synthesis of β-amino alcohols under solvent-free conditions

“…The high catalytic activity of developed G2 catalyst can also be attributed to the mesoporous nature of the beads with a high surface area (550 m 2 g À1 ), leading to superior mass transfer and pore diffusion. 42,43 It is relevant to highlight that the same reaction when conducted without catalyst did not proceed to any appreciable extent even aer 12 h where only 44% yield was obtained (Table 2, entry 5). a M 2+ -divalent transition metals: Ni, Cu, Fe, and Co. b The yield refers to isolated product aer column purication.…”

Preparation and characterization of supermacroporous polyacrylamide cryogel beads for biotechnological application

“…Both polymeric (natural and synthetic) and inorganic materials can be used for the fabrication of porous beads. The material should be carefully selected for specific applications …”