Pancreatic lipase (PL) is an important enzyme which has been widely used in chemical and pharmaceutical industries. To improve the activity and stability of PL is of great significance in the relevant fields of research and development. It has been recognized that immobilization of PL on preferable solid surface is a good approach to achieve this goal. Various methods have been evaluated for immobilizing PL, and several of them have been successfully used in chemical engineering industry.

However, study on PL immobilization on magnetic nanoparticles (MNPs) has been inadequate up to date. In addition, little is known about the potential of reusable PL-MNP nano-composites in screening lipase inhibitors, which is highly desired in anti-obesity drug discovery.

Researchers in Chengdu Institute of Biolgoy, Chinese Academy of Sciences synthesized a new type of porcine pancreatic lipase-superparamagnetic nanoparticle nano-composite (MNPs-PPL) by using carboxyl functionalized silica-coated magnetic nanoparticles (MNPs) as carrier, and demonstrated its applicability in screening of lipase inhibitors. PPL was covalently attached to the surface of magnetic nanoparticles with a PPL immobilization yield of 50mg enzyme/g MNPs, and the MNPs-PPL had a high saturation magnetization of 42.25 emu/g. Catalyzing activity, reusability, thermo-stability and storage stability of the prepared MNPs-PPL were found significantly superior to those of free PPL.

By using these nano-composites, facile lipase inhibition assays was carried out using orlistat, and two natural products isolated from oolong tea (i.e., EGCG and EGC) as the test compounds. This new functionalized magnetic material showed great potential in the screening of lipase inhibitors from natural products. This work has been published in Materials Science and Engineering C.