Borah Rituparna, Mamidi Narsimha, Panda Subhankar, Gorai Sukhamoy, Pathak Suraj Kumar, Manna Debasis
Department of Chemistry, Indian Institute of Technology Guwahati, Assam 781039, India.
Mol Biosyst. 2015 May;11(5):1389-99. doi: 10.1039/c5mb00100e.
The protein kinase C (PKC) family of proteins is an attractive drug target. Dysregulation of PKC-dependent signalling pathways is related to several human diseases like cancer, immunological and other diseases. We approached the problem of altering PKC activities by developing C1 domain-based PKC ligands. In this report γ-hydroxymethyl-γ-butyrolactone (HGL) substituents were investigated in an effort to develop small molecule-based PKC regulators with higher specificity for C1 domain than the endogenous diacylglycerols (DAGs). Extensive analysis of membrane-ligands interaction measurements revealed that the membrane-active compounds strongly interact with the lipid bilayers and the hydrophilic parts of compounds localize at the bilayer/water interface. The pharmacophores like hydroxymethyl, carbonyl groups and acyl-chain length of the compounds are crucial for their interaction with the C1 domain proteins. The potent compounds showed more than 17-fold stronger binding affinity for the C1 domains than DAG under similar experimental conditions. Nonradioactive kinase assay confirmed that these potent compounds have similar or better PKC dependent phosphorylation capabilities than DAG under similar experimental conditions. Hence, our findings reveal that these HGL analogues represent an attractive group of structurally simple C1 domain ligands that can be further structurally altered to improve their potencies.
蛋白激酶C（PKC）家族蛋白是一个具有吸引力的药物靶点。PKC依赖的信号通路失调与多种人类疾病相关，如癌症、免疫性疾病及其他疾病。我们通过开发基于C1结构域的PKC配体来解决改变PKC活性的问题。在本报告中，对γ-羟甲基-γ-丁内酯（HGL）取代基进行了研究，旨在开发对C1结构域具有比内源性二酰基甘油（DAG）更高特异性的小分子PKC调节剂。对膜-配体相互作用测量的广泛分析表明，膜活性化合物与脂质双层强烈相互作用，且化合物的亲水性部分位于双层/水界面。化合物的药效基团如羟甲基、羰基和酰基链长度对其与C1结构域蛋白的相互作用至关重要。在相似实验条件下，强效化合物对C1结构域的结合亲和力比对DAG强17倍以上。非放射性激酶测定证实，在相似实验条件下，这些强效化合物具有与DAG相似或更好的PKC依赖性磷酸化能力。因此，我们的研究结果表明，这些HGL类似物代表了一组有吸引力的结构简单的C1结构域配体，可进一步进行结构改造以提高其效力。
