Reductive alkylation of lipase: experimental and molecular modeling approaches

Rahman, R.N.Z.A. and Salleh, A.B. and Siahaan, T.J. and Zain, S.M. and Khan, F. and Rahman, M.B.A. and Basri, M. and Tejo, B.A. (2004) Reductive alkylation of lipase: experimental and molecular modeling approaches. Applied Biochemistry and Biotechnology - Part A Enzyme Engineering and Biotechnology, 118 (1-3). pp. 11-20. ISSN 02732289

Full text not available from this repository. (Request a copy)
Official URL: http://www.scopus.com/inward/record.url?eid=2-s2.0...

Abstract

Candida rugosa lipase was modified via reductive alkylation to increase its hydrophobicity to work better in organic solvents. The free amino group of lysines was alkylated using propionaldehyde with different degrees of modification obtained (49 and 86%). Far-ultraviolet circular dichroism (CD) spectroscopy of the lipase in aqueous solvent showed that such chemical modifications at the enzyme surface caused a loss in secondary and tertiary structure that is attributed to the enzyme unfolding. Using molecular modeling, we propose that in an aqueous environment the loss in protein structure of the modified lipase is owing to disruption of stabilizing salt bridges, particularly of surface lysines. Indeed, molecular modeling and simulation of a salt bridge formed by Lys-75 to Asp-79, in a nonpolar environment, suggests the adoption of a more flexible alkylated lysine that may explain higher lipase activity in organic solvents on alkylation.

Item Type: Article
Additional Information: Department of Chemistry, Faculty of Science Building, University of Malaya, 50603 Kuala Lumpur, MALAYSIA
Uncontrolled Keywords: Candida rugosa, Circular dichroism, Enzyme modification, Lipase, Molecular modeling, aspartic acid, fungal enzyme, lysine, organic solvent, propionaldehyde, triacylglycerol lipase, alkylation, aqueous solution, chemical modification, conference paper, enzyme structure, hydrophobicity, molecular model, protein folding, protein structure, reduction, simulation, ultraviolet radiation, Candida, Hydrogen Bonding, Models, Molecular, Oxidation-Reduction, Transferases
Subjects: Q Science > QD Chemistry
Divisions: Faculty of Science > Dept of Chemistry
Depositing User: Miss Malisa Diana
Date Deposited: 22 Apr 2013 01:38
Last Modified: 22 Apr 2013 01:38
URI: http://eprints.um.edu.my/id/eprint/5850

Actions (login required)

View Item View Item