白腐真菌Trametes sp. SQ01漆酶的新功能:转化2-羟基-6氧-6-苯基-2，4-己二烯酸

New function of laccase from Trametes sp．SQ01:transforming 2-hydroxy-6-oxo-6-phenylhexa-2，4-dienoate

摘要:

摘要:【目的】利用白腐真菌Trametes sp．SQ01漆酶转化2-羟基-6氧-6-苯基-2，4-己二烯酸(HOPDAs)，可以帮助我们进一步了解漆酶新的催化特性及解决多氯联苯降解过程中HOPDAs的积累问题。【方法】利用紫外可见光谱分析法，研究了漆酶对8种不同取代基的HOPDAs的转化情况，并对漆酶的稳态动力学参数进行了测定。【结果】漆酶可以在没有任何中介物的条件下催化HOPDAs，并生成无色的物质，尤其是漆酶可以催化3，8，11-3Cl HOPDA，而这一物质几乎不能被BphD和Rhodococcus sp．R04 转化。稳态动力学分析表明，在5种HOPDAs中，10-Cl HOPDA是漆酶的最适底物，其Km与HOPDA和8-Cl HOPDA相近。尽管3，10-2F HOPDA并不是漆酶的最适底物(Km=17.02 μmol/L)，但是它的转化效率(kcat/Km)是最高的。【结论】漆酶可以有效转化多种HOPDAs，这为多氯联苯的降解提供一种新的思路。

关键词:关键词:2-羟基-6氧-6-苯基-2，4-己二烯酸(HOPDAs)，漆酶，催化作用

Abstract:

Abstract:［Objective］ To study the transformation of 2-hydroxy-6-oxo-6-phenylhexa-2，4-dienoates (HOPDAs) by laccase from Trametes sp．SQ01 so to further understand the new catalytic properties of laccase and solve the problem of accumulations of HOPDAs in polychlorinated biphenyls (PCBs) degradation. ［Methods］ With UV-vis spectrophotometer，we studied the transformations of 8 substituted HOPDAs by laccase，and measured the steady-state kinetics parameters of laccase against parts of HOPDAs.［Results］ Laccase catalyzed HOPDAs to colorless substances without any mediators; among them，especially 3，8，11-3Cl HOPDA that was barely transformed by 2-hydroxy-6-oxo-6-phenylhexa-2，4-dienoate hydrolase (BphD) and Rhodococcus sp．R04，also could be transformed by this laccase．The analysis of the steady-state kinetics indicated that 10-Cl HOPDA was the optimal substrate of laccase among 5 HOPDAs，and the Km was lower than that of HOPDA and 8-Cl HOPDA．Although 3，10-2F HOPDA was not the optimal substrate (Km=17.02 μmol/L)，its transformation efficiency (kcat/Km) was the highest.［Conclusion］Laccase from Trametes sp. SQ01could transform various HOPDAs effectively，and has its potential in eliminating PCB pollution.

Key words:Keywords: HOPDAs (2-hydroxy-6-oxo-6-phenylhexa-2，4-dienoates)，laccase，catalysis