Ceccon Alberto, Busato Mirko, Pérez Santero Silvia, D'Onofrio Mariapina, Musiani Francesco, Giorgetti Alejandro, Assfalg Michael
Department of Biotechnology, Biomolecular NMR Laboratory, University of Verona, Strada Le Grazie 15, 37134, Verona, Italy.
Department of Biotechnology, Applied Bioinformatics Laboratory, University of Verona, Strada Le Grazie 15, 37134, Verona, Italy.
Chembiochem. 2015 Dec;16(18):2633-45. doi: 10.1002/cbic.201500451. Epub 2015 Nov 6.
Cytosolic proteins do not occur as isolated but are exposed to many interactions within a crowded cellular environment. We investigated the associations between a test cytosolic protein, human ileal bile acid binding protein (IBABP), and model cosolutes mimicking macromolecular and lipid membrane intracellular components. Using fluorescence spectroscopy, heteronuclear NMR, and molecular dynamics, we found that IBABP associated weakly with anionic lipid vesicles and experienced transient unspecific contacts with albumin. Localized dynamic perturbations were observed even in the case of apparent unspecific binding. IBABP and ubiquitin did not display mutually attractive forces, whereas IBABP associated specifically with lysozyme. A structural model of the IBABP-lysozyme complex was obtained by data-driven docking simulation. Presumably, all the interactions shown here contribute to modulating functional communication of a protein in its native environment.
胞质蛋白并非孤立存在，而是在拥挤的细胞环境中会发生多种相互作用。我们研究了一种测试性胞质蛋白——人回肠胆汁酸结合蛋白（IBABP）与模拟大分子和脂质膜细胞内成分的模型共溶质之间的关联。通过荧光光谱法、异核核磁共振和分子动力学，我们发现IBABP与阴离子脂质囊泡的结合较弱，且与白蛋白有短暂的非特异性接触。即使在明显的非特异性结合情况下，也观察到了局部动态扰动。IBABP和泛素之间没有表现出相互吸引力，而IBABP与溶菌酶有特异性结合。通过数据驱动的对接模拟获得了IBABP - 溶菌酶复合物的结构模型。据推测，此处所示的所有相互作用都有助于调节蛋白质在其天然环境中的功能通讯。
