title: Arthrobacter sp. lipase immobilization for improvement in stability and enantioselectivity.
abstract: Arthrobacter sp. lipase (ABL, MTCC no. 5125) is being recognized as an efficient enzyme for the resolution of drugs and their intermediates. The immobilization of ABL on various matrices for its enantioselectivity, stability, and reusability has been studied. Immobilization by covalent bonding on sepharose and silica afforded a maximum of 380 and 40 IU/g activity, respectively, whereas sol-gel entrapment provided a maximum of 150 IU/g activity in dry powder. The immobilized enzyme displayed excellent stability in the pH range of 4-10 and even at higher temperature, i.e., 50-60 degrees C, compared to free enzyme, which is unstable under extreme conditions. The resolution of racemic auxiliaries like 1-phenyl ethanol and an intermediate of antidepressant drug fluoxetine, i.e., ethyl 3-hydroxy-3-phenylpropanoate alkyl acylates, provided exclusively R-(+) products ( approximately 99% ee, E=646 and 473), compared to cell free extract/whole cells which gave a product with approximately 96% ee (E=106 and 150). The repeated use (ten times) of covalently immobilized and entrapped ABL resulted in no loss in activity, thus demonstrating its prospects for commercial applications.
authors.affiliation: Regional Research Laboratory CSIR, Canal Road, Jammu Tawi 180001, India.
authors.forename: Asha
authors.initials: A
authors.lastname: Chaubey
authors.forename: Rajinder
authors.initials: R
authors.lastname: Parshad
authors.forename: Surrinder
authors.initials: S
authors.lastname: Koul
authors.forename: Subhash C
authors.initials: SC
authors.lastname: Taneja
authors.forename: Ghulam N
authors.initials: GN
authors.lastname: Qazi
mesh_terms: D001173:Arthrobacter / Q000201:enzymology*; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology; D007700:Kinetics; D008049:Lipase / Q000737:chemistry* / Q000378:metabolism; D019998:Racemases and Epimerases / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013379:Substrate Specificity; D013696:Temperature; D014871:Water Microbiology
chemical_list: D004800:Enzymes, Immobilized; D012997:Solvents; D008049:Lipase; D019998:Racemases and Epimerases