Flavonoids are a class of polyphenols that possess diverse properties. The structure‐activity relationship of certain flavonoids and resveratrol with ribonuclease A (RNase A) has been investigated. The selected flavonoids have a similar skeleton and the positional preferences of the phenolic moieties toward inhibition of the catalytic activity of RNase A have been studied. The results obtained for RNase A inhibition by flavonoids suggest that the planarity of the molecules is necessary for effective inhibitory potency. Agarose gel electrophoresis and precipitation assay experiments along with kinetic studies reveal K_i values for the various flavonoids in the micromolar range. Minor secondary structural changes of RNase A were observed after interaction with the flavonoids. An insight into the specific amino acid involvement in the binding of the substrate using docking studies is also presented. The dipole moment of the flavonoids that depends on the orientation of the hydroxyl groups in the molecule bears direct correlation with the inhibitory potency against RNase A. The direct association of this molecular property with enzyme inhibition can be exploited for the design and development of inhibitors of proteins.

中文翻译：

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类黄酮抑制核糖核酸酶 A 的位置偏好：“？OH”在哪里？

类黄酮是一类具有多种特性的多酚。已经研究了某些黄酮类化合物和白藜芦醇与核糖核酸酶 A (RNase A) 的构效关系。选定的类黄酮具有相似的骨架，并且研究了酚部分对抑制 RNase A 催化活性的位置偏好。黄酮类化合物抑制 RNase A 的结果表明分子的平面性对于有效抑制效力是必要的。琼脂糖凝胶电泳和沉淀试验以及动力学研究揭示了K _i微摩尔范围内各种黄酮类化合物的值。在与类黄酮相互作用后观察到 RNase A 的次要二级结构变化。还介绍了使用对接研究参与底物结合的特定氨基酸。取决于分子中羟基方向的黄酮类化合物的偶极矩与对 RNase A 的抑制效力直接相关。这种分子特性与酶抑制的直接关联可用于设计和开发 RNase A 的抑制剂。蛋白质。