Structure–function analysis of a new bacterial lipase: Effect of local structure reorganization on lipase activity

Abstract: Like many other bacterial lipases Pseudomonas aeruginosa lipase has a very strong structure–function relationship. Herein, the effect of structural compactness of lipase has been investigated on its activity. P. aeruginosa HR59 was isolated from burn infection as a new and inexpensive source. Bacterial lipase was extracted from this strain and purified by ion-exchange chromatography. Two divalent metal ions (calcium and magnesium) and three polar organic solvents (methanol, ethanol and iso-propanol) were used to study the structure–function relationship. Results of this study revealed that these additives activated enzyme by reducing the helix content of enzyme. Moreover, thermo stability of the enzyme decreased in the presence of calcium and magnesium ions; whereas it increased upon interaction with polar organic solvents under heat-induced denaturation. Results of this investigation encourage utilization of these activity enhancers for various medical and industrial applications. [Copyright &y& Elsevier]