Istituto Pasteur, Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari del CNR , Sapienza Università di Roma , 00185 , Rome , Italy.
J Phys Chem B. 2018 Dec 13;122(49):11108-11114. doi: 10.1021/acs.jpcb.8b05651. Epub 2018 Aug 7.
SHP2 is a phosphatase protein, involved in many cellular pathways, comprising two SH2 domains (namely N-SH2 and C-SH2) and a phosphatase domain. Among others, the interaction between SHP2 and Gab2 (Grb2 associated binder) is critical in cell death and differentiation. SHP2 binds to Gab2 through its SH2 domains, which recognize specific regions of Gab2 characterized by the presence of a phosphorylated tyrosine. In order to shed light on the dynamic and functional properties of this protein-protein interaction, we studied the mechanism of folding of N-SH2 and the binding process to a peptide mimicking a region of Gab2. The data presented represent the first description by stopped-flow of the kinetics of binding of an SH2 domain in solution. By performing experiments at different ionic strengths, we elucidate the electrostatic nature of the interaction, highlighting a key role of the negative charge of the phosphotyrosine in the recognition event of the reaction. Furthermore, by analyzing the equilibrium and kinetics of folding of N-SH2 folding we demonstrate the presence of an intermediate along the folding pathway. These results are discussed in the light of previous works on another SH2 domain.
SHP2 是一种磷酸酶蛋白，参与许多细胞途径，包括两个 SH2 结构域（即 N-SH2 和 C-SH2）和一个磷酸酶结构域。在其他方面，SHP2 与 Gab2（Grb2 相关结合蛋白）之间的相互作用对于细胞死亡和分化至关重要。SHP2 通过其 SH2 结构域与 Gab2 结合，这些结构域识别 Gab2 中存在磷酸化酪氨酸的特定区域。为了阐明这种蛋白质-蛋白质相互作用的动态和功能特性，我们研究了 N-SH2 的折叠机制和与模拟 Gab2 区域的肽的结合过程。所呈现的数据代表了通过停流技术首次描述了溶液中 SH2 结构域的结合动力学。通过在不同离子强度下进行实验，我们阐明了相互作用的静电性质，突出了磷酸酪氨酸的负电荷在反应识别事件中的关键作用。此外，通过分析 N-SH2 折叠的平衡和动力学，我们证明了在折叠途径中存在中间产物。这些结果在另一个 SH2 结构域的先前工作的基础上进行了讨论。
