Premium
Kinetic behaviour and stability of glucose oxidase entrapped in liposomes
Author(s) -
RodriguezNogales José Manuel
Publication year - 2004
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.944
Subject(s) - liposome , choline oxidase , glucose oxidase , enzyme , chemistry , cholesterol oxidase , chromatography , biochemistry , oxidase test , substrate (aquarium) , enzyme assay , biology , acetylcholinesterase , ecology
Glucose oxidase (EC 1.1.3.4) was encapsulated in liposomes (prepared from phosphatidyl choline and cholesterol) by the dehydration–rehydration method. The enzymatic activities of native and liposomal glucose oxidase were followed by the amount of H 2 O 2 obtained in the enzymatic β‐ D ‐glucose oxidation. Some characteristics of the liposomal and free glucose oxidase were compared. The enzyme encapsulated in liposomes showed an apparent inhibition by glucose at concentrations higher than 0.28 mol dm −3 with a substrate inhibition constant of 0.95 ± 0.12 mol dm −3 . The enzyme entrapped showed an apparent K m value higher than that of the free enzyme. The apparent V max of liposomal enzyme decreased by a factor of 0.35 with respect of that of the native enzyme. The optimum temperature of the free and entrapped enzymes remained similar but the liposomal enzyme showed maximal activity at a more acid pH (5.2). The thermal and proteolytic stabilities were enhanced by encapsulation in liposomes. The stabilization factors (relationship between half‐lives of entrapped form and free enzyme) at 45, 50 and 55 °C for liposomal glucose oxidase were 2.6, 1.6 and 1.6, respectively. Copyright © 2003 Society of Chemical Industry