Institute of Biostructures and Bioimaging (CNR), Naples, Italy; InterUniversity Research Centre on Bioactive Peptides (CIRPEB), University of Naples Federico II, Naples, Italy.
University of Naples Federico II, Department of Pharmacy, Naples, Italy.
Bioorg Chem. 2019 Mar;84:434-443. doi: 10.1016/j.bioorg.2018.12.009. Epub 2018 Dec 8.
EphA2 receptor plays a critical and debatable function in cancer and is considered a target in drug discovery. Lately, there has been a growing interest in its cytosolic C-terminal SAM domain (EphA2-SAM) as it engages protein modulators of receptor endocytosis and stability. Interestingly, EphA2-SAM binds the SAM domain from the lipid phosphatase Ship2 (Ship2-SAM) mainly producing pro-oncogenic outcomes. In an attempt to discover novel inhibitors of the EphA2-SAM/Ship2-SAM complex with possible anticancer properties, we focused on the central region of Ship2-SAM (known as Mid-Loop interface) responsible for its binding to EphA2-SAM. Starting from the amino acid sequence of the Mid-Loop interface virtual peptide libraries were built through ad hoc inserted mutations with either l- or d- amino acids and screened against EphA2-SAM by docking techniques. A few virtual hits were synthesized and experimentally tested by a variety of direct and competition-type interaction assays relying on NMR (Nuclear Magnetic Resonance), SPR (Surface Plasmon Resonance), MST (Microscale Thermophoresis) techniques. These studies guided the discovery of an original EphA2-SAM ligand antagonist of its interaction with Ship2-SAM.
EphA2 受体在癌症中发挥着关键且有争议的作用，被认为是药物发现的靶点。最近，人们对其胞质 C 端 SAM 结构域（EphA2-SAM）越来越感兴趣，因为它与受体内化和稳定性的蛋白调节剂结合。有趣的是，EphA2-SAM 主要与脂质磷酸酶 Ship2 的 SAM 结构域（Ship2-SAM）结合，从而产生致癌作用。为了发现具有潜在抗癌特性的 EphA2-SAM/Ship2-SAM 复合物的新型抑制剂，我们专注于 Ship2-SAM 的中心区域（称为 Mid-Loop 界面），该区域负责与 EphA2-SAM 结合。从 Mid-Loop 界面的氨基酸序列开始，通过专门插入的 l-或 d-氨基酸构建虚拟肽文库，并通过对接技术筛选 EphA2-SAM。一些虚拟命中物被合成，并通过依赖 NMR（核磁共振）、SPR（表面等离子体共振）、MST（微尺度热泳）技术的各种直接和竞争型相互作用测定法进行了实验测试。这些研究指导了发现一种与 Ship2-SAM 相互作用的 EphA2-SAM 配体拮抗剂。
