title: Protein-coated microcrystals of Pseudomonas aeruginosa PseA lipase.
abstract: Highly active Pseudomonas aeruginosa lipase protein-coated microcrystals (PAL PCMC) have been prepared by immobilization of protein onto K(2)SO(4) as excipient solid support carrier and n-propanol as precipitating solvent. Transmission electron micrographs confirmed the formation of PAL PCMC. These PCMC were found to be a catalytically more active and stable preparation for p-nitrophenyl palmitate hydrolysis in n-heptane, compared to free lipase. The V (max), K (m), and temperature optimum for PAL PCMC increased from 0.49 to 5.66 nmol min(-1) mg(-1), 589 to 679.8 mmol, and 40 degrees C to 45 degrees C, respectively. These were thermally more stable with 4.65, 2.56, and 1.24-fold improvement in half lives at 45 degrees C, 55 degrees C, and 60 degrees C compared to free P. aeruginosa PseA lipase. Their catalytic efficiency was enhanced by tenfold over that of free enzyme. PAL PCMC offer a simple and effective technique for obtaining stable and efficient lipase preparation for biocatalysis in nonaqueous medium.
authors.affiliation: Chemistry Department, Indian Institute of Technology, Hauz Khas, New Delhi, India.
authors.forename: Ruchi
authors.initials: R
authors.lastname: Gaur
authors.forename: G N
authors.initials: GN
authors.lastname: Gupta
authors.forename: M
authors.initials: M
authors.lastname: Vamsikrishnan
authors.forename: S K
authors.initials: SK
authors.lastname: Khare
mesh_terms: D003460:Crystallization; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry*; D007700:Kinetics; D008049:Lipase / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D011550:Pseudomonas aeruginosa / Q000201:enzymology
chemical_list: D004800:Enzymes, Immobilized; D008049:Lipase