title: Highly efficient "tight fit" immobilization of alpha-chymotrypsin in mesoporous MCM-41: a novel approach using precursor immobilization and activation.
abstract: The zymogen alpha-chymotrypsinogen A is bound to mesoporous silica MCM-41 with a protein loading of 170 mg/g solid (MCM-Z) by a simple stirring in aqueous tris-HCl buffer (pH 7.2). The bound zymogen is then activated with trypsin to obtain alpha-chymotrypsin immobilized on MCM-41 (MCM-E.I) that displays an effective enzyme activity corresponding to 65 mg protein/g of solid support (3250 BTEE units/g). A direct immobilization of commercially available alpha-chymotrypsin (MCM-E.II) gives lower loading (1250 BTEE units/g). Protein content of the solid support after immobilization is confirmed by thermogravimetric analysis (TGA). The enzyme is tightly bound to the support and can be used over 100 recycles over 1 week in aqueous as well as reverse micellar media. The immobilized enzyme (MCM-E.I) has been used for resolution of N-acetyl-dl-amino acid esters and racemic trans-4-methoxy-3-phenylglycidic acid (PGA) methyl ester.
authors.affiliation: Biotransformations Laboratory, Organic Division-I, and Inorganic Chemistry Division, Indian Institute of Chemical Technology, Hyderabad-500 007, India.
authors.forename: Nitin W
authors.initials: NW
authors.lastname: Fadnavis
authors.forename: Veldurthy
authors.initials: V
authors.lastname: Bhaskar
authors.forename: Mannepalli Lakshmi
authors.initials: ML
authors.lastname: Kantam
authors.forename: Boyapati Manoranjan
authors.initials: BM
authors.lastname: Choudary
mesh_terms: D002918:Chymotrypsin / Q000138:chemical synthesis; D002919:Chymotrypsinogen / Q000737:chemistry*; D004789:Enzyme Activation; D004792:Enzyme Precursors / Q000737:chemistry*; D004795:Enzyme Stability; D004800:Enzymes, Immobilized; D016062:Porosity; D011487:Protein Conformation; D012822:Silicon Dioxide / Q000737:chemistry*; D014357:Trypsin / Q000737:chemistry*
chemical_list: D004792:Enzyme Precursors; D004800:Enzymes, Immobilized; D012822:Silicon Dioxide; D002919:Chymotrypsinogen; D002918:Chymotrypsin; C117608:alpha-chymotrypsin; D014357:Trypsin