Megaporous poly(hydroxy ethylmethacrylate) based poly(glycidylmethacrylate-N-methacryloly-(L)-tryptophan) embedded
Deniz Türkmen1, Nilay Bereli1, Ali Derazshamshir1
1Department of Chemistry, Biochemistry Division, Hacettepe University, Ankara, Turkey.
Abstract:
One-step activation, purification, and stabilization of lipase enzyme were performed by using composite hydrophobic support at low ionic strength with increased surface area during embedding process. A novel hydrophobic poly(hydroxyethylmethacrylate) [PHEMA] based, poly(glycidyl methacrylate-N-methacryloly-(L)-tryptophan) [PGMATrp] bead embedded composite cryogel membrane having specific surface area of 195m(2)/g was used as hydrophobic matrix for adsorption of commercial Candida Rugosa lipase in a continuous system. PGMATrp embedded PHEMA cryogel membrane with 60-100 μm pore size was obtained by dispersion polymerization of GMA and MATrp to form PGMATrp beads followed by embedding of PGMATrp to HEMA via APS and TEMED redox pair. The introduction of hydrophobic MATrp monomer into bead structure aiming to increase interaction between lipase and composite membrane was estimated using nitrogen stoichiometry of elemental analysis and found to be 239 μmol/g of polymer. Hydophobicity increment due to embedding process was confirmed by measuring contact angle, it was found 42° and 48.4° for the PHEMA and PHEMA/PGMATrp composite cryogel respectively. Some parameters i.e. pH, flow-rate, protein concentration, temperature, salt type and ionic intensity were evaluated on the adsorption capacity in a continuous system. Fast protein liquid chromatography (FPLC) studies were performed for specific adsorption of lipase onto the PHEMA/PGMATrp embedded composite cryogel membrane.
