Dambrova M, Uhlén S, Welch C J, Wikberg J E
Department of Pharmaceutical Biosciences, Uppsala University, Sweden.
Eur J Biochem. 1998 Oct 1;257(1):178-84. doi: 10.1046/j.1432-1327.1998.2570178.x.
A guanoxabenz [1-(2,6-dichlorobenzylideneamino)-3-hydroxyguanidine; an N-hydroxyguanidine] reducing enzymatic activity of rat spleen cytosol was investigated. By means of protein purification and N-terminal amino acid sequencing, the reducing activity was shown to reside in xanthine oxidase. The action of the enzyme on guanoxabenz resulted in the formation of guanabenz [1-(2,6-dichlorobenzylidene-amino)-3-guanidine]; the product formation could be monitored by HPLC and its identity was confirmed by NMR analysis. The reduction of guanoxabenz required xanthine or NADH as reducing substrates, while the process could be blocked by allopurinol, a selective inhibitor of xanthine oxidase. By using bovine milk xanthine oxidase, the guanoxabenz reducing activity of the enzyme was also verified. We conclude that guanoxabenz is a novel electron acceptor structure for xanthine oxidase.
对胍诺苄[1-(2,6-二氯亚苄基氨基)-3-羟基胍；一种N-羟基胍]降低大鼠脾细胞溶质酶活性进行了研究。通过蛋白质纯化和N端氨基酸测序，发现还原活性存在于黄嘌呤氧化酶中。该酶对胍诺苄的作用导致胍那苄[1-(2,6-二氯亚苄基氨基)-3-胍]的形成；产物形成可通过高效液相色谱法监测，其结构通过核磁共振分析得以确认。胍诺苄的还原需要黄嘌呤或烟酰胺腺嘌呤二核苷酸作为还原底物，而该过程可被黄嘌呤氧化酶的选择性抑制剂别嘌呤醇阻断。通过使用牛乳黄嘌呤氧化酶，也验证了该酶对胍诺苄的还原活性。我们得出结论，胍诺苄是黄嘌呤氧化酶的一种新型电子受体结构。
