title: Sol-gel immobilization of serine proteases for application in organic solvents.
abstract: The serine proteases alpha-chymotrypsin, trypsin, and subtilisin Carlsberg were immobilized in a sol-gel matrix and the effects on the enzyme activity in organic media are evaluated. The percentage of immobilized enzyme is 90% in the case of alpha-chymotrypsin and the resulting specific enzyme activity in the transesterification of N-acetyl-L-phenylalanine ethyl ester with 1-propanol in cyclohexane is 43 times higher than that of a nonimmobilized lyophilized alpha-chymotrypsin. The activities of trypsin and subtilisin Carlsberg are enhanced with 437 and 31 times, respectively. The effect of immobilization on the enzyme activity is highest in hydrophobic solvents.
authors.affiliation: Laboratory of Supramolecular Chemistry and Technology, MESA Research Institute, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: D J
authors.initials: DJ
authors.lastname: van Unen
authors.forename: J F
authors.initials: JF
authors.lastname: Engbersen
authors.forename: D N
authors.initials: DN
authors.lastname: Reinhoudt
mesh_terms: D002849:Chromatography, Gas; D002918:Chymotrypsin / Q000032:analysis; D004795:Enzyme Stability; D004800:Enzymes, Immobilized; D004951:Esterification; D007700:Kinetics; D011487:Protein Conformation; D012697:Serine Endopeptidases / Q000378:metabolism*; D012821:Silanes / Q000494:pharmacology*; D012997:Solvents / Q000494:pharmacology*; D013010:Sonication; D020860:Subtilisin / Q000032:analysis; D014357:Trypsin / Q000032:analysis
chemical_list: D004800:Enzymes, Immobilized; D012821:Silanes; D012997:Solvents; C071718:methyltrimethoxysilane; C061205:tetramethoxysilane; D012697:Serine Endopeptidases; D002918:Chymotrypsin; C117608:alpha-chymotrypsin; D014357:Trypsin; D020860:Subtilisin