Clark S K, Conroy J M, Harris P J
Mol Immunol. 1983 Dec;20(12):1379-84. doi: 10.1016/0161-5890(83)90169-4.
Inhibition of the catalytic activity of horseradish peroxidase by rabbit antisera was measured using alternate enzyme substrates. The same general inhibition curve patterns were obtained regardless of the electron donor or hydroperoxide used. In all cases typical biphasic inhibition patterns were found and complete inhibition of enzyme activity was never observed. Measurement of the degree of inhibition as a function of substrate concn revealed a dependence of anticatalytic activity on hydroperoxide concn. As the concn of hydrogen peroxide in the assay mixture increased, there was a corresponding increase in the inhibition observed. On the other hand, the degree of inhibition was not dependent on the concn of electron donor (dianisidine) in the assay mixture. Spectrophotometric experiments with an electron donor analogue demonstrated that antibodies do not inhibit peroxidase activity by excluding electron donor molecules from enzyme binding sites. The results have suggested possible mechanisms for the antibody-mediated inhibition of peroxidase activity.
使用替代酶底物测量兔抗血清对辣根过氧化物酶催化活性的抑制作用。无论使用何种电子供体或氢过氧化物，均获得相同的一般抑制曲线模式。在所有情况下均发现典型的双相抑制模式，且从未观察到酶活性的完全抑制。测量抑制程度与底物浓度的函数关系表明，抗催化活性依赖于氢过氧化物浓度。随着测定混合物中过氧化氢浓度的增加，观察到的抑制作用相应增加。另一方面，抑制程度不依赖于测定混合物中电子供体（联茴香胺）的浓度。用电子供体类似物进行的分光光度实验表明，抗体不会通过将电子供体分子排除在酶结合位点之外来抑制过氧化物酶活性。这些结果提示了抗体介导的过氧化物酶活性抑制的可能机制。
