| Abstract: | A fatty acid hydroperoxide lyase of mung beans has been covalently immobilized on different commercially available gels which represents the first immobilization of this type of enzyme from a higher plant. UltraLink Iodoacetyl possessed optimum coupling properties and yielded a maximum activity of 1.3 U ml–1 gel and a yield of 84%. The effect of various protective reagents (e.g. thiols, antioxidants) and of the substrate concentration on the re-usability of the immobilized enzyme was investigated. Compared to a control, the relative activity during re-use was enhanced 1.8- to 2.3-fold in the presence of dithiothreitol. As the hydroperoxide lyase was irreversibly inhibited by the substrate, its re-usability depended strongly on the hydroperoxide concentration. The lowest inactivation was with 55  M hydroperoxide which resulted in a relative activity of 73% after the third cycle. The storage stability of the hydroperoxide lyase was significantly improved by immobilization and resulted in a relative activity of 86% after 18 days, whereas the soluble enzyme lost 68% of its initial activity. © Rapid Science Ltd. 1998 |
