Supermacroporous hydrophobic affinity cryogels for protein chromatography


YILMAZ F., BERELİ N., Yavuz H., DENİZLİ A.

BIOCHEMICAL ENGINEERING JOURNAL, vol.43, no.3, pp.272-279, 2009 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 43 Issue: 3
  • Publication Date: 2009
  • Doi Number: 10.1016/j.bej.2008.10.009
  • Journal Name: BIOCHEMICAL ENGINEERING JOURNAL
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.272-279
  • Hacettepe University Affiliated: Yes

Abstract

N-Methacryloyl-L-tryptophan (MATrp) containing poly(2-hydroxyethyl methacrylate) based supermacroporous cryogel [PHEMATrp] was prepared for lysozyme purification form chicken egg white. MATrp was synthesized by reacting methacryloyl chloride with L-tryptophan methyl ester and provided hydrophobic functionality to the cryogel. PHEMATrp cryogel with 60-100 mu m pore size was obtained by free radical polymerization of HEMA and MATrp having a specific surface area of 50m(2)/g. PHEMATrp cryogel was characterized by swelling studies, FTIR and SEM. The equilibrium swelling ratios of the cryogels were 7.18g H2O/g for PHEMA and 6.99 g H2O/g for PHEMATrp. Lysozyme adsorption experiments were investigated under different conditions in continuous system (i.e., medium pH, flow-rate, protein concentration, temperature, salt type). Lysozyme adsorption capacity of PHEMA and PHEMATrp cryogels from aqueous solutions was estimated as 2.9 and 46.8 mg/g (0.49 and 7.85 mg/mL), respectively. Lysozyme molecules were desorbed with 0.5 M ethylene glycol solution with 91% recovery. It was observed that PHEMATrp cryogel can be used without significant decrease in lysozyme adsorption capacity after five adsorption-desorption cycles. PHEMATrp cryogel was used for the purification of lysozyme from chicken egg white. Purity of lysozyme was estimated by SDS-PAGE. Possible denaturation of purified lysozyme was checked with fluorimetric measurements. Specific activity of the purified lysozyme was found as 43,140 U/mg using Micrococcus lysodeikticus as substrate. (C) 2008 Elsevier B.V. All rights reserved.