A Cyclic Peptide Inhibitor of the iNOS–SPSB Protein–Protein Interaction as a Potential Anti-Infective Agent
作者:Maiada M. Sadek、Nicholas Barlow、Eleanor W. W. Leung、Billy J. Williams-Noonan、Beow Keat Yap、Fairolniza Mohd Shariff、Tom T. Caradoc-Davies、Sandra E. Nicholson、David K. Chalmers、Philip E. Thompson、Ruby H. P. Law、Raymond S. Norton
DOI:10.1021/acschembio.8b00561
日期:2018.10.19
targeted for degradation. Inhibition of this interaction increases iNOS levels, and consequently cellular nitric oxide (NO) concentrations, and has been proposed as a potential strategy for killing intracellular pathogens. We previously described two DINNN-containing cyclic peptides (CP1 and CP2) as potent inhibitors of the murine SPSB–iNOS interaction. In this study, we report the crystal structures
包含SPRY域和SOCS框的蛋白质SPSB1,SPSB2和SPSB4与诱导型一氧化氮合酶(iNOS)相互作用,导致iNOS被多泛素化并靶向降解。抑制这种相互作用会增加iNOS的水平,从而增加细胞中一氧化氮(NO)的浓度,因此,有人提出将其作为杀死细胞内病原体的潜在策略。我们先前描述了两种含DINNN的环肽(CP1和CP2)作为鼠SPSB–iNOS相互作用的有效抑制剂。在这项研究中,我们报告人SPSB4绑定到CP1和CP2的晶体结构和人SPSB2绑定到CP2的晶体结构。然后,我们使用这些结构设计了一种新的抑制剂,其中分子内的氢键被烃键取代,从而形成了一个较小的大环,同时保持了晶体结构中观察到的CP2的结合几何形状。这种产生的五肽SPSB–iNOS抑制剂(CP3)具有减小的大环环大小,较少的非结合残基,并包括其他构象约束。CP3对SBSB2的亲和力更大(K D = 7 nM,由表面等离振子共振