Gaur Ruchi, Gupta G N, Vamsikrishnan M, Khare S K
Chemistry Department, Indian Institute of Technology, Hauz Khas, New Delhi, India.
Appl Biochem Biotechnol. 2008 Dec;151(2-3):160-6. doi: 10.1007/s12010-008-8163-x. Epub 2008 Aug 9.
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.
通过将蛋白质固定在作为赋形剂固体支持载体的硫酸钾和作为沉淀溶剂的正丙醇上，制备了高活性的铜绿假单胞菌脂肪酶蛋白包被微晶（PAL PCMC）。透射电子显微镜照片证实了PAL PCMC的形成。与游离脂肪酶相比，发现这些PCMC在正庚烷中对棕榈酸对硝基苯酯水解具有更高的催化活性和稳定性。PAL PCMC的V（max）、K（m）和最适温度分别从0.49增加到5.66 nmol min(-1) mg(-1)、从589增加到679.8 mmol、从40℃增加到45℃。与游离铜绿假单胞菌PseA脂肪酶相比，它们在45℃、55℃和60℃下的热稳定性更高，半衰期分别提高了4.65倍、2.56倍和1.24倍。它们的催化效率比游离酶提高了十倍。PAL PCMC提供了一种简单有效的技术，用于获得在非水介质中进行生物催化的稳定高效脂肪酶制剂。
