磺酰脲除草剂与过氧化氢酶的相互作用

应用荧光光谱法研究了水溶液中氯磺隆、甲磺隆、苄嘧磺隆与过氧化氢酶分子间的结合反应.结果表明,3种除草剂对过氧化氢酶的荧光均有较强的猝灭作用,且形成复合物所产生的静态猝灭是引起过氧化氢酶荧光猝灭的主要原因.进一步根据荧光猝灭结果确定了除草剂-酶复合物的形成常数和结合位点数.氯磺隆:K=8.69×105L·mol-1,n=1.16;甲磺隆:K=1.01×106L·mol-1,n=1.21;苄嘧磺隆:K=3.52×103L·mol-1,n=0.77.由此可见,3种除草剂与过氧化氢酶的结合作用:甲磺隆＞氯磺隆＞苄嘧磺隆.

Study on Interaction between Sulfonylurea Herbicides and Catalase by Fluorescence Spectroscopy

The binding of Sulfonylurea herbicides to catalase in aqueous solution was studied using fluorescence spectroscopy. It was shown that herbicides have a strong ability to quench the catalase fluorescence mainly through a static quenching procedure. The binding constant K and the number of binding site n were calculated according to the fluorescence quenching results. For chlorsufuron, K=8.69 x 10(5) L x mol(-1) and n = 1.16; for metsufuron methyl, K = 1.01 x 10(6) L x mol(-1) and n = 1.21; and for bensufuron methyl, K = 3.52 x 10(3) L x mol(-1), n = 0.77. It is clear that the binding of metsufuron methyl with catalase is stronger than that of chlorsufuron, while the binding of chlorsufuron stronger than that of bensufuron methyl.