Abstract
Water-insoluble lipoprotein lipase (LPL) was prepared by immobilizing LPL onto the surface of porous copoly (γ- methyl-L-glutamate / L-leucine) (ML) beads with and without spacer.The mode of theimmobilization between LPL and porous copolypeptido ML beads was covalent fixation.The relative activity and the stability of the immobilized LPL was investigated.The retained activity of the LPLcovalently immobilized by the azide method was found to be excellent toward a small ester substrate,p-nitrophenyllaurate (pNPL). The values of the Michaelis constant Km, and the maximum reaction velocityVm for free and immobilized LPL on the porous copolypeptide ML beads were estimated.Apparent Kmwas larger for immobilized LPL than for the free one, while Vm was smaller for the immobilized LPL.The thermal stability of the covalently immobilized LPL was higher than that of the freeLPL.The initial enzymatic activity of the immobilized LPL remained approximately unchanged withstorage time, when the batch enzyme reaction was performed repeatedly, indicating the excellent durability.
