Løvstad R A
Int J Biochem. 1987;19(4):309-13. doi: 10.1016/0020-711x(87)90003-6.
The inhibitory effect of catalase and superoxide dismutase on copper catalyzed oxidation of ascorbate is probably due to a binding of copper ions. Scavengers of hydroxyl ions and singlet oxygen had no effect on the ascorbate oxidation rate. Copper binding serum proteins reduced the oxidation rate; the order of effectiveness being: Ceruloplasmin greater than human albumin = bovine albumin greater than apotransferrin. The excellent protection obtained with catalase and ceruloplasmin is possibly due to a strong affinity for cuprous ions generated during the reaction. Cupric ion binding amino acids (His, Thr, Glu, Gln, Tyr) had considerably weaker protective effect than the proteins studied. Apparently they do not compete favorably with ascorbate for cupric ions.
过氧化氢酶和超氧化物歧化酶对铜催化的抗坏血酸氧化的抑制作用可能归因于铜离子的结合。氢氧根离子和单线态氧的清除剂对抗坏血酸的氧化速率没有影响。铜结合血清蛋白降低了氧化速率；有效性顺序为：铜蓝蛋白＞人白蛋白 = 牛白蛋白＞脱铁转铁蛋白。用过氧化氢酶和铜蓝蛋白获得的优异保护作用可能是由于对反应过程中生成的亚铜离子具有很强的亲和力。与所研究的蛋白质相比，铜离子结合氨基酸（组氨酸、苏氨酸、谷氨酸、谷氨酰胺、酪氨酸）的保护作用要弱得多。显然，它们在与抗坏血酸竞争铜离子方面不占优势。
