Tainer J A, Getzoff E D, Richardson J S, Richardson D C
Nature. 1983;306(5940):284-7. doi: 10.1038/306284a0.
Copper, zinc superoxide dismutase (SOD) catalyses the very rapid two-step dismutation of the toxic superoxide radical (O-2) to molecular oxygen and hydrogen peroxide through the alternate reduction and oxidation of the active-site copper. We report here that after refitting and further refinement of the previous 2 A structure of SOD2, analysis of the new model and its calculated molecular surface shows an extensive surface topography of sequence-conserved residues stabilized by underlying tight packing and H-bonding. There is a single, highly complementary position for O-2 to bind to both the Cu(II) and activity-important Arg 141 with correct geometry; two water molecules form a ghost of the superoxide in this position. The geometry and molecular surface of the active site, together with biochemical data, suggest a specific model for the enzyme mechanism.
铜锌超氧化物歧化酶（SOD）通过活性位点铜的交替还原和氧化，催化毒性超氧阴离子自由基（O₂⁻）非常快速地两步歧化为分子氧和过氧化氢。我们在此报告，在对先前SOD2的2 Å结构进行重新拟合和进一步优化后，对新模型及其计算出的分子表面的分析表明，由潜在的紧密堆积和氢键稳定的序列保守残基具有广泛的表面形貌。对于O₂⁻，存在一个单一的、高度互补的位置，可与Cu(II)和对活性重要的精氨酸141以正确的几何构型结合；两个水分子在该位置形成超氧阴离子的假象。活性位点的几何构型和分子表面，连同生化数据，提示了酶作用机制的一个特定模型。
