Ceccon Alberto, Tugarinov Vitali, Boughton Andrew J, Fushman David, Clore G Marius
Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda, Maryland 20892-0520, United States.
Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland , College Park, Maryland 20742-4454, United States.
J Phys Chem Lett. 2017 Jun 1;8(11):2535-2540. doi: 10.1021/acs.jpclett.7b01019. Epub 2017 May 24.
The interactions of two model multidomain proteins-covalently linked diubiquitins, Ub-with lipid-based nanoparticles have been quantitatively probed by the measurements of NMR lifetime line broadening, ΔR. By combined analysis of ΔR profiles arising from interactions with liposomes of varying sizes, an approach recently developed for the characterization of interactions of monoubiquitin with liposomes, we determine how the parameters of exchange (liposome binding) and dynamics of each individual domain of Ub on the surface of liposomes change when the domains are covalently attached to one another by a flexible linker. Two different covalent linkages were used: K63-linked and K48-linked Ub. The possibility of three distinct modes of binding of Ub to liposomes requires the introduction of simple but important modifications to the strategy of analysis originally developed for monoubiquitin.
通过测量核磁共振寿命线宽展（ΔR），对两种模型多结构域蛋白——共价连接的双泛素（Ub）与脂质基纳米颗粒之间的相互作用进行了定量探究。通过对与不同大小脂质体相互作用产生的ΔR图谱进行综合分析（这是最近开发的一种用于表征单泛素与脂质体相互作用的方法），我们确定了当各结构域通过柔性接头共价连接在一起时，泛素在脂质体表面的交换（脂质体结合）参数和每个结构域的动力学是如何变化的。使用了两种不同的共价连接：K63连接的和K48连接的Ub。Ub与脂质体存在三种不同结合模式的可能性，要求对最初为单泛素开发的分析策略进行简单但重要的修改。
