Research Group Structural and Medicinal Biochemistry, ZMB, University of Duisburg-Essen, 45117 Essen, Germany.
Structure. 2013 Oct 8;21(10):1769-77. doi: 10.1016/j.str.2013.07.016. Epub 2013 Aug 22.
The mitotic regulator Pin1 plays an important role in protein quality control and age-related medical conditions such as Alzheimer disease and Parkinson disease. Although its cellular role has been thoroughly investigated during the past decade, the molecular mechanisms underlying its function remain elusive. We provide evidence for interactions between the two domains of Pin1. Several residues displayed unequivocal peak splits in nuclear magnetic resonance spectra, indicative of two different conformational states in equilibrium. Pareto analysis of paramagnetic relaxation enhancement data demonstrates that the two domains approach each other upon addition of a nonpeptidic ligand. Titration experiments with phosphorylated peptides monitored by fluorescence anisotropy and chemical shift perturbation indicate that domain interactions increase Pin1's affinity toward peptide ligands. We propose this interplay of the domains and ligands to be a general mechanism for a large class of two-domain proteins.
有丝分裂调节剂 Pin1 在蛋白质质量控制和与年龄相关的医学病症（如阿尔茨海默病和帕金森病）中发挥着重要作用。尽管在过去十年中，其细胞作用已被彻底研究，但它的功能的分子机制仍难以捉摸。我们提供了 Pin1 两个结构域之间相互作用的证据。在核磁共振光谱中，几个残基显示出明确的峰分裂，表明存在两种不同的平衡构象状态。顺磁弛豫增强数据分析的帕累托分析表明，在添加非肽配体时，两个结构域相互靠近。通过荧光各向异性和化学位移扰动监测的磷酸化肽滴定实验表明，结构域相互作用增加了 Pin1 对肽配体的亲和力。我们提出，这种结构域和配体的相互作用是一大类双结构域蛋白的一般机制。
