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. 2018 Oct;80:602-610. doi: 10.1016/j.bioorg.2018.07.013. Epub 2018 Jul 20.
Sam (Sterile alpha motif) domains represent small helical protein-protein interaction modules which play versatile functions in different cellular processes. The Sam domain from the EphA2 receptor binds the Sam domain of the lipid phosphatase Ship2 and this interaction modulates receptor endocytosis and degradation primarily generating pro-oncogenic effects in cell. To identify molecule antagonists of the EphA2-Sam/Ship2-Sam complex with anti-cancer activity, we focused on hydrocarbon helical stapled peptides. EphA2-Sam and one of its interactors (i.e., the first Sam domain of the adaptor protein Odin) were used as model systems for peptide design. Increase in helicity in the stapled peptides, with respect to the corresponding linear/native-like regions, was proved by structural studies conducted through CD (Circular Dichroism) and NMR (Nuclear Magnetic Resonance). Interestingly, interaction assays by means of NMR, SPR (Surface Plasmon Resonance) and MST (MicroScale Thermophoresis) techniques led to the discovery of a novel ligand of Ship2-Sam.
Sam（无菌α基序）结构域代表小型螺旋蛋白-蛋白相互作用模块，在不同的细胞过程中发挥多种功能。EphA2 受体的 Sam 结构域与脂质磷酸酶 Ship2 的 Sam 结构域结合，这种相互作用调节受体的内吞和降解，主要在细胞中产生致癌作用。为了鉴定具有抗癌活性的 EphA2-Sam/Ship2-Sam 复合物的分子拮抗剂，我们专注于碳氢化合物螺旋订书肽。EphA2-Sam 及其一种相互作用蛋白（即衔接蛋白 Odin 的第一个 Sam 结构域）被用作肽设计的模型系统。通过通过 CD（圆二色性）和 NMR（核磁共振）进行的结构研究证明，订书肽相对于相应的线性/天然样区域增加了螺旋度。有趣的是，通过 NMR、SPR（表面等离子体共振）和 MST（微量热泳动）技术进行的相互作用测定导致发现了 Ship2-Sam 的一种新型配体。
