Effect of lysine residue modification on stability and activity of candida rugosa lipase

Abstract

To improve the thermostability and organic solvent stability of the lipase, chemical modifications of the enzyme were performed. Lysine residues of Candida rugosa lipase were acetylated and succinylated, and activity and stability of these modified enzymes were examined in reversed micelle system. UV difference adn flurosence spectroscopic studies were also performed to et some information about structural changes of the modifiedenzyme. Both actylation and succinylation resulted in increase of substrate affinity, thermal stability and organic solvent stability of the enzyme. And there was no significant structrual changes by the modification. From the results of the modification, at least one of the cysteine, histidine and tyrosine residue was involved in active site of the enzyme and the histidine residue is most probable. Lysine residue was not involved in active site of the enzyme.