Polyethylene glycol modification ofCandida rugosa lipase

Abstract

Polyethylene glycol (PEG) was covalently attached to lipase (EC 3.1.1.3) fromCandida rugosa yielding a modified lipase of higher specific activity in hydrolytic and synthetic reactions in organic solvents. PEG of molecular weights 5000 and 1900 solubilized the lipase in selected organic solvents, but PEG of molecular weight 750 was too small to accomplish this completely. The modified lipase was 10 times more stable in water than native lipase, but was less stable in benzene. The selectivity of the modified lipase was also altered to favor reaction with oleic versus stearic acid.

Influence of the nature of modifier in the enzymatic activity of chemical modified semipurified lipase fromCandida rugosa

“…Similar results have been reported by Ampon et al (1991) using alkyl-lipase as biocatalyst in the esterification of oleic acid in benzene, and this is in agreement with observations made by Klibanov (Volkin et al, 1991;Zaks and Klibanov, 1984) and Baillergeou and Sonnet (1988). We can observe that stability increases with the modification degree, and thus CRSL-pNPCF-1/30 is the most stable derivative.…”

“…In the case of CRSL-pNPCF this value is higher than the modification degree obtained by Basri et al (1995) (55%), who worked with a different kind of enzyme (C. rugosa Type IV, M w 120,000) and under other experimental conditions. In the case of CRSL-CC, Baillergeou and Sonnet (1988) described a 10-fold molar excess of the activated PEG to free amino groups of the commercial lipase and obtained 36% modification. The small chemical modification percentage obtained by these authors can be explained by the presence of many impurities (glycopeptides, lactose) in the commercial powder (Rúa et al, 1993).…”

Evaluation of Lipid Modified Lipase for Interesterification and Hydrolysis Reactions in n-Hexane.

“…In addition, organic reaction media improves substrate solubility and stability and aids facile product recovery (Dordick, 1989;Klibanov, 1990). However, crude lipases typically show little or no activity in organic solvents, hence methods to irnprove both the activity and stability are of particular importance (Baillargeon & Sonnet, 1988;Basri et al, 1992).…”

Evaluation of immobilized modified lipase: Aqueous preparation and reaction studies in n‐hexane

“…Hydrolysis [mmol FFA/(g·h)] and interesterification activities [mmol PPS/(g ⋅ h)] using SA IML after 4 h with continuous batch reactions(1)(2)(3)(4). For reaction 5 no water was added to the reaction media.…”

“…Recent attention has focused on using lipases for the conversion of fats and oils to produce high-value products (1,2). Lipases typically show little or no activity in organic solvents, hence, methods to improve both activity and stability are of particular importance (3,4). Enzyme coating by oil-soluble surfactants and lipids has greatly enhanced activity in organic media (5)(6)(7)(8)(9).…”