New cationic exchanger support for reversible immobilization of proteins.
New tailor-made cationic exchange resins have been prepared by covalently binding aspartic-dextran polymers (e.g. MW 15 000-20 000) to porous supports (aminated agarose and Sepabeads). More than 80% of the proteins contained in crude extracts from Escherichia coli and Acetobacter turbidans have been strongly adsorbed on these porous materials at pH 5. This interaction was stronger than in conventional carboxymethyl cellulose (e.g., at pH 7 and 25 degrees C, all proteins previously adsorbed at pH 5 were released from carboxymethyl cellulose, whereas no protein was released from the new supports under similar conditions). Ionic exchange properties of such composites were strongly dependent on the size of the aspartic-dextran polymers as well as on the exact conditions of the covalent coating of the solids with the polymer (optimal conditions: 100 mg aspartic-dextran 20 000/(mL of support); room temperature). Finally, some industrially relevant enzymes (Kluyveromices lactis, Aspergillus oryzae, and Thermus sp. beta-galactosidases, Candida antarctica B lipase, and bovine pancreas trypsin and chymotrypsin) have been immobilized on these supports with very high activity recovery and immobilization rates. After enzyme inactivation, the enzyme can be fully desorbed from the support and the support could be reused for several cycles.
Fuentes
Manuel
M
Laboratorio de Tecnología Enzimática, Departamento de Biocatálisis, Instituto de Catálisis y Petroleoquímica-CSIC, Campus Universidad Autónoma, Cantoblanco, 28049 Madrid, Spain.
Maquiese
Jorgete V
JV
Pessela
Benevides C C
BC
Abian
Olga
O
Fernández-Lafuente
Roberto
R
Mateo
Cesar
C
Guisán
J M
JM
D000327:Adsorption; D001224:Aspartic Acid / Q000737:chemistry*; D001426:Bacterial Proteins / Q000737:chemistry*; D002411:Cation Exchange Resins / Q000138:chemical synthesis / Q000737:chemistry*; D003911:Dextrans / Q000737:chemistry*; D004798:Enzymes / Q000737:chemistry*; D004800:Enzymes, Immobilized / Q000737:chemistry; D011485:Protein Binding; D012685:Sepharose / Q000737:chemistry*
D001426:Bacterial Proteins; D002411:Cation Exchange Resins; D003911:Dextrans; D004798:Enzymes; D004800:Enzymes, Immobilized; D001224:Aspartic Acid; D012685:Sepharose