The relative significance of weak non-covalent interactions in biological context has been much debated. Here, we have addressed the contribution of Coulombic interactions to protein stability and assembly experimentally. The sweet protein monellin, a non-covalently linked heterodimeric protein, was chosen for this study because of its ability to spontaneously reconstitute from separated fragments. The reconstitution of monellin mutants containing large surface charge perturbations was compared to the thermostability of structurally equivalent single-chain monellin containing the same sets of mutations under varying salt concentrations. The affinity between monellin fragments is found to correlate with the thermostability of single chain monellin, indicating the involvement of the same underlying Coulombic interactions. This confirms that there are no principal differences in the interactions involved in folding and binding. Based on comparison with a previous mutational study involving hydrophobic core residues, the relative contribution of Coulombic interactions to stability and affinity is modest. However, the Coulombic perturbations only affect the association rates of reconstitution in contrast to perturbations involving hydrophobic residues, which affect primarily the dissociation rates. These results indicate that Coulombic interactions are likely to be of main importance for the association of protein assembly, relevant for functions of proteins.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.jmb.2006.02.069 | DOI Listing |
Nat Commun
January 2025
Department of Physics and Competence Centre for Catalysis, Chalmers University of Technology, SE-412 96, Göteborg, Sweden.
The performance of Cu-exchanged chabazite (Cu-CHA) for the ammonia-assisted selective catalytic reduction of NO (NH-SCR) depends critically on the presence of paired complexes. Here, a machine-learning force field augmented with long-range Coulomb interactions is developed to investigate the effect of Al-distribution and Cu-loading on the mobility and pairing of complexes. Performing unbiased and constrained molecular dynamics simulations, we obtain unique information inaccessible to first-principle calculations and experiments.
View Article and Find Full Text PDFSmall
January 2025
Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, China.
A novel polymer electrolyte based on CsPbI quantum dots (QDs) reinforced polyacrylonitrile (PAN), named as PIL, is exploited to address the low room-temperature (RT) ion conductivity and poor interfacial compatibility of polymer solid-state electrolytes. After optimizing the content of CsPbI QDs, RT ion conductivity of PIL largely increased from 0.077 to 0.
View Article and Find Full Text PDFJ Mol Model
January 2025
INIFTA, DQT, Sucursal 4, C. C. 16, 1900, La Plata, Argentina.
Quantum mechanics has proved to be suitable for the study of molecular systems. In particular, the Born-Oppenheimer approximation enables one to separate the motions of electrons and nuclei. In the case of diatomic molecules, this approximation leads to the so-called potential-energy function that provides the interaction between the two nuclei.
View Article and Find Full Text PDFSmall
January 2025
Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, P. R. China.
Although Silicon monoxide (SiO) is regarded as the most promising next-generation anode material, the large volume expansion, poor conductivity, and low initial Coulombic efficiency (ICE) severely hamper its commercialization application. Designing a multilayer conductive skeleton combined with advanced prelithiation technology is considered an effective approach to address these problems. Herein, a reliable strategy is proposed that utilizes MXene and carbon nanotube (CNT) as dual-conductive skeletons to encapsulate SiO through simple electrostatic interaction for high-performance anodes in LIBs, while also performing chemical prelithiation.
View Article and Find Full Text PDFACS Nano
January 2025
Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus C 8000, Denmark.
Superlattices from twisted graphene mono- and bilayer systems give rise to on-demand many-body states such as Mott insulators and unconventional superconductors. These phenomena are ascribed to a combination of flat bands and strong Coulomb interactions. However, a comprehensive understanding is lacking because the low-energy band structure strongly changes when an electric field is applied to vary the electron filling.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!