@article { ISI:000298518600028, title = {Adsorption induced enzyme denaturation: the role of protein surface in adsorption induced protein denaturation on allyl glycidyl ether (AGE)-ethylene glycol dimethacrylate (EGDM) copolymers}, journal = {Colloids and Surfaces B-Biointerfaces}, volume = {90}, year = {2012}, month = {FEB}, pages = {184-190}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The effects of protein size on adsorption and adsorption-induced denaturation of proteins on copolymers of allyl glycidyl ether (AGE)-ethylene glycol dimethacrylate (EGDM) have been studied. Different responses were observed for the amount of protein adsorbed and denatured on the polymer surface for different proteins (trypsin, alchol dehydrogenase from baker{\textquoteright}s yeast (YADH), glucose dehydrogenase (GDH) from Gluconobacter cerinus, and alkaline phosphates from calf intestinal mucosa (CIAP). Protein adsorption on the copolymer with 25\% crosslink density (AGE-25) was dependent not only on the size of the protein but also on the presence of glycoside residues on the protein surface. Adsorption and denaturation of proteins follows the order YADH \> trypsin \> GDH \>\> CIAP although the molecular weights of the proteins follow the order YADH \> CIAP \> GDH \> trypsin. The lack of correlation between amount of adsorbed protein and its molecular weight was due to the presence of glycoside residues on CIAP and GDH which protect the enzyme surface from denaturation. Enzyme stabilities in aqueous solutions of 1-cyclohexyl-2-pyrrolidinone (CHP) correlate well with the trend in denaturation by the copolymer, strongly suggesting that hydrophobic interactions play a major role in protein binding and the mechanism of protein denaturation is similar to that for water-miscible organic solvents. (C) 2011 Elsevier B.V. All rights reserved.

}, keywords = {1-Cyclohexyl-2-pyrrolidinone, Adsorption, Alcohol dehydrogenase, Alkaline phosphatase, allyl glycidyl ether, Denaturation, ethylene glycol dimethacrylate, Glucose dehydrogenase, Trypsin}, issn = {0927-7765}, doi = {10.1016/j.colsurfb.2011.10.022}, author = {Thudi, Lahari and Jasti, Lakshmi Swarnalatha and Swarnalatha, Y. and Fadnavis, Nitin W. and Mulani, Khudbudin Baban and Deokar, Sarika Babasaheb and Ponrathnam, Surendra} } @article { ISI:000335706100026, title = {Comparison of polymer induced and solvent induced trypsin denaturation: the role of hydrophobicity}, journal = {Colloids and Surfaces B-Biointerfaces}, volume = {116}, year = {2014}, month = {APR}, pages = {201-205}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Trypsin adsorption from aqueous buffer by various copolymers of allyl glycidyl ether-ethylene glycol dimethacrylate (AGE-EGDM) copolymer with varying crosslink density increases with increasing crosslink density and the effect slowly wears off after reaching a plateau at 50\% crosslink density. The copolymer with 25\% crosslink density was reacted with different amines with alkyl/aryl side chains to obtain a series of copolymers with 1,2-amino alcohol functional groups and varying hydrophobicity. Trypsin binding capacity again increases with hydrophobicity of the reacting amine and a good correlation between logP(octanol) of the amine and protein binding is observed. The bound trypsin is denatured to the extent of 90\% in spite of the presence of hydrophilic hydroxyl and amino groups. The behavior was comparable to that in mixtures of aqueous buffer and water-miscible organic co-solvents where the solvent concentration required to deactivate 50\% of the enzyme (C-50) is dependent on logP(octanol) of the co-solvent. (C) 2014 Elsevier B.V. All rights reserved.

}, keywords = {Adsorption, Denaturation, Hydrophobicity, Polymer, Trypsin}, issn = {0927-7765}, doi = {10.1016/j.colsurfb.2014.01.002}, author = {Jasti, Lakshmi Swarnalatha and Fadnavis, Nitin W. and Addepally, Uma and Daniels, Siona and Deokar, Sarika Babasaheb and Ponrathnam, Surendra} } @article { ISI:000334421100007, title = {Protein-coated polymer as a matrix for enzyme immobilization: immobilization of trypsin on bovine serum albumin-coated allyl glycidyl ether-ethylene glycol dimethacrylate copolymer}, journal = {Biotechnology Progress}, volume = {30}, number = {2}, year = {2014}, month = {MAR}, pages = {317-323}, publisher = {WILEY-BLACKWELL}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

Allyl glycidyl ether (AGE)-ethylene glycol dimethacrylate (EGDM) copolymer with 25\% crosslink density (AGE-25) shows excellent bovine serum albumin (BSA) adsorption (up to 16\% (w/w)) at pH 8.0 and the adsorbed BSA is strongly bound. This protein-coated polymer provides a novel matrix with naturally existing functional groups such as thiol, amino, and carboxylic acid that are available for covalent immobilization of functional enzymes. Employing appropriate strategies, trypsin as a model protein was covalently bound to BSA-coated matrix both independently, and in a stepwise manner on the same matrix, with less than 5\% loss of enzyme activity during immobilization. Glutaraldehyde crosslinking after immobilization provide stable enzyme preparation with activity of 510 units/g recycled up to six times without loss of enzyme activity. AFM studies reveal that the polymer surface has protein peaks and valleys rather than a uniform monolayer distribution of the protein and the immobilized enzyme preparation can best be described as polymer supported cross-linked enzyme aggregates (CLEAs). (c) 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:317-323, 2014

}, keywords = {allyl glycidyl ether, Bovine serum albumin, ethylene glycol dimethacrylate, Immobilization, Trypsin}, issn = {8756-7938}, doi = {10.1002/btpr.1871}, author = {Jasti, Lakshmi Swarnalatha and Dola, Sandhya Rani and Kumaraguru, Thenkrishnan and Bajja, Sreedhar and Fadnavis, Nitin W. and Addepally, Uma and Rajdeo, Kishor and Ponrathnam, Surendra and Deokar, Sarika Babasaheb} }