Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, United States.
Bioorg Med Chem. 2011 Sep 15;19(18):5321-33. doi: 10.1016/j.bmc.2011.08.008. Epub 2011 Aug 11.
Resveratrol (1) is a naturally occurring phytoalexin that affects a variety of human disease models, including cardio- and neuroprotection, immune regulation, and cancer chemoprevention. One of the possible mechanisms by which resveratrol affects these disease states is by affecting the cellular signaling network involving protein kinase C alpha (PKCα). PKCα is a member of the family of serine/threonine kinases, whose activity is inhibited by resveratrol. To study the structure-activity relationship, several monoalkoxy, dialkoxy and hydroxy analogs of resveratrol have been synthesized, tested for their cytotoxic effects on HEK293 cells, measured their effects on the membrane translocation properties of PKCα in the presence and absence of the PKC activator TPA, and studied their binding with the activator binding domain of PKCα. The analogs showed less cytotoxic effects on HEK293 cells and caused higher membrane translocation (activation) than that of resveratrol. Among all the analogs, 3, 16 and 25 showed significantly higher activation than resveratrol. Resveratrol analogs, however, inhibited phorbol ester-induced membrane translocation, and the inhibition was less than that of resveratrol. Binding studies using steady state fluorescence spectroscopy indicated that resveratrol and the analogs bind to the second cysteine-rich domain of PKCα. The molecular docking studies indicated that resveratrol and the analogs interact with the protein by forming hydrogen bonds through its hydroxyl groups. These results signify that molecules developed on a resveratrol scaffold can attenuate PKCα activity and this strategy can be used to regulate various disease states involving PKCα.
白藜芦醇（1）是一种天然存在的植物抗毒素，它影响多种人类疾病模型，包括心脏和神经保护、免疫调节和癌症化学预防。白藜芦醇影响这些疾病状态的可能机制之一是通过影响涉及蛋白激酶 C 阿尔法（PKCα）的细胞信号网络。PKCα 是丝氨酸/苏氨酸激酶家族的成员，其活性被白藜芦醇抑制。为了研究构效关系，已经合成了几种白藜芦醇的单烷氧基、二烷氧基和羟基类似物，测试了它们对 HEK293 细胞的细胞毒性作用，测量了它们在存在和不存在 PKC 激活剂 TPA 的情况下对 PKCα 膜易位特性的影响，并研究了它们与 PKCα 的激活剂结合域的结合。类似物对 HEK293 细胞的细胞毒性作用较小，引起的膜易位（激活）高于白藜芦醇。在所有类似物中，3、16 和 25 显示出比白藜芦醇更高的激活作用。然而，白藜芦醇类似物抑制佛波酯诱导的膜易位，其抑制作用小于白藜芦醇。使用稳态荧光光谱学的结合研究表明，白藜芦醇和类似物通过其羟基与 PKCα 的第二个富含半胱氨酸的结构域结合。分子对接研究表明，白藜芦醇和类似物通过形成氢键与蛋白质相互作用。这些结果表明，基于白藜芦醇支架开发的分子可以减弱 PKCα 的活性，并且可以使用这种策略来调节涉及 PKCα 的各种疾病状态。
