尿素对磺酰脲除草剂与过氧化氢酶相互作用的影响  

Effects of Urea on Interactions between Sulfonylurea Herbicides and Catalase by Fluorescence Spectroscopy

作　　者：叶发兵[1] 董元彦[1] 胡记童[2] 莫小曼[2] 胡先文[1] 

机构地区：[1]华中农业大学理学院化学系,湖北武汉430070 [2]黄冈师范学院化学系,湖北黄冈438000

出　　处：《化学与生物工程》2007年第2期25-28,共4页Chemistry & Bioengineering

基　　金：湖北省自然科学基金项目(2006ABA187)

摘　　要：应用荧光光谱法研究了水溶液中尿素对氯磺隆、甲磺隆与过氧化氢酶分子间的结合反应的影响。结果表明,两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。未添加尿素时,氯磺隆K=8.69×105L.mol-1,n=1.16;甲磺隆K=1.01×106L.mol-1,n=1.21。添加尿素混用后,氯磺隆K=2.82×106L.mol-1,n=1.08;甲磺隆K=3.63×107L.mol-1,n=1.14。并根据能量转移机制,求出了氯磺隆、甲磺隆及其与尿素混用等四种情况下,给能体和供能体间距分别为5.60 nm、4.26 nm、3.69 nm、3.65 nm。由此可见,两种除草剂与过氧化氢酶的结合作用在未添加尿素时,甲磺隆大于氯磺隆;添加尿素后,甲磺隆和氯磺隆与过氧化氢酶的结合作用增强。The effects of urea on the binding of using fluorescence spectroscopy. It was shown that sulfonylurea herbicides to catalase in aqueous were studied herbicides had strong abilities 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,when urea was not used, for chlorsulfuron, K =8.69×10^5 L·mol^-1 and n=1.16; for metsulfuron methyl, K=1.01×10^6 L- tool 1 and n=1. 21; when u- rea was used,for chlorsulfuron, K=2.82×10^6 L·mol^-1,n=1.08; for metsulfuron methyl, K=3.63×10^7 L · mol^-1,n=1.14. Based on the mechanism of energy transfer, the distances between acceptor herbicide and CAT were obtained as 5.60 nm, 4.26 nm,3.69 nm, 3.65 nm, respectively. It was clear that the binding of metsulfuron methyl with catalase was stronger than that of chlorsulfuron and when urea was used, the bindings of metsulfuron methyl and chlorsulfuron with catalase both got stronger than that when urea was not used.

关 键 词：氯磺隆 甲磺隆 尿素 过氧化氢酶 荧光光谱 

分 类 号：X132[环境科学与工程—环境科学]