Gel-immobilized enzymes as promising biocatalysts: Results from Indo-Russian collaborative studies*
Elena A. Markvicheva1,‡, Vladimir I. Lozinsky2, Fatima M. Plieva2, Konstantin A. Kochetkov2, Lev D. Rumsh1, Vitali P. Zubov1, Jyotirmoy Maity3, Rajesh Kumar3, Virinder S. Parmar3, and Yury N. Belokon2
1Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya St. 16/10, Moscow 117871, Russia; 2Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov St. 28, Moscow, V-334, 117813, Russia; 3Bioorganic Laboratory, Department of Chemistry, University of Delhi, Delhi 110 007, India
Abstract: Chemo-enzymatic methods constitute a promising approach to obtain various biologically active compounds, including enantiomerically pure substances. Entrapment in gels is one of the most convenient methods to stabilize enzymes for their application in water/organic media. Proteases and lipases are widely used for enantioselective transformations of various organic compounds in water-poor media. In this study, chymotrypsin was entrapped into a composite poly(N-vinyl caprolactam)-calcium alginate (PVCL-CaAlg) and covalently attached to poly(vinyl alcohol) (PVA) cryogel beads. Lipase was immobilized by covalently attaching to aldehyde-bearing PVA cryogel beads. The activities of the entrapped biocatalysts were studied. Both entrapped α-chymotrypsin and lipase retained high activity in acetonitrile/water medium (water content 0.5–20 %) and displayed high storage stability for several months. The high operational stability of immobilized α-chymotrypsin and lipase in a cyclic process (up to 912 h in total) was also demonstrated. Gel-immobilized enzymes were successfully used to obtain optically pure L-phenylalanine (ee 98.6 and 83 % in the case of α‑chymotrypsin and lipase, respectively) by enantioselective hydrolysis of Schiff’s base of amino acid ethyl ester in an acetonitrile/water system.
*Paper based on a presentation at the 24th International Symposium on the Chemistry of Natural Products and the 4th International Congress on Biodiversity, held jointly in Delhi, India, 26-31 January 2004. Other presentations are published in this issue, pp. 1-344.