非离子反胶束中木素过氧化物酶催化性能研究

Studies on the Catalytic Performance of Lignin Peroxidase in Nonionic Reversed Micelles

木素过氧化物酶(LiP)在环己烷/Brij30/水反胶束体系中可体现催化活力,然而在水/醇/TritonX-100/环己烷反胶束体系中却没有催化活力。对影响Brij30反胶束中LiP催化活力各主要因素进行了优化并测定了LiP在其中的时间稳定性;结果表明,20℃下,使LiP体现最佳活力的Brij30反胶束介质条件为:ω0=8·5,pH=2·2,[Brij30]=600mmol/L;在此条件下,LiP的半衰期可达到50h;与水介质相比,酶活力下降了,但稳定性却提高了。直链醇是TritonX-100形成反胶束的必要组分,为揭示醇的作用,还考察了戊醇对Brij30反胶束中LiP催化活力的影响,发现高浓度戊醇对LiP有失活作用。据此推测助表面活性剂醇可能是LiP在环己烷/TritonX-100/戊醇/水反胶束中不能体现催化活力的主要原因。

Lignin peroxidase (LiP) hosted in Brij 30/cyclohexane/water nonionic reversed micelle could express its catalytic activity, but in Triton X-100/n-pentanol/cyclohexane/water nonionic reversed micelle LiP didn't show any catalytic activity. Some key factors that affected the catalytic activity of LiP in Brij 30 reversed micelle were studied at 20℃. The optimum conditions were:ω0=8.5, pH=2.2, [Brij30]=600mmol/L; under these conditions the half time of LiP was ca.50 hours. As compared with the properties of LiP in aqueous solution, the activity of LiP hosted in Brij 30 reversed micelle dropped, but its stability improved greatly. To reveal the role of normal alcohol, which was a necessary component for forming Triton X-100 reversed micelles, the effect of n-pentanol on the catalytic activity of LiP in Brij 30 reversed micelle was investigated. Results indicated that high concentration of the alcohol deactivated LiP. So it was deduced that the phenomenon that LiP hosted in the Triton X-100 reversed micelles could not express its activity was mainly due to the alcohol co-surfactant.