Dynamics of Ionic Interactions at Protein–Nucleic Acid Interfaces

• DOI: 10.1021/acs.accounts.0c00212
• Publication Date: 2020-08-26T19:01:30Z
• Authors: Binhan Yu; B. Montgomery Pet...; Junji Iwahara
• Keywords: Ions; 0303 health sciences; 03 medical and health sciences; Lysine; Nucleic Acids; Static Electricity; Proteins; Thermodynamics; Molecular Dynamics Simulation; Arginine; Phosphates; Protein Binding

ConspectusMolecular association of proteins with nucleic acids is required for many biological processes essential to life. Electrostatic interactions via ion pairs (salt bridges) acid phosphates and protein side chains are crucial bind DNA or RNA. Counterions around the macromolecules also key constituents thermodynamics protein–nucleic association. Until recently, there had been only a limited amount experiment-based information about how ions ionic moieties behave in macromolecular processes. In past decade, has significant progress quantitative experimental research on their complexes proteins. The highly negatively charged surfaces RNA electrostatically attract condense cations, creating zone called atmosphere. Recent studies were able examine validate theoretical models mobility macromolecules. dynamic. counterions rapidly diffuse within Some released from atmosphere when acids, balancing charge intermolecular positively backbone phosphates. Previously, release implicated indirectly by salt-concentration dependence constant.Recently, direct detection counterion NMR spectroscopy become possible enabled more accurate analysis its entropic impact revealed dynamic nature These undergo transitions between two major states. one states, cation anion contact form hydrogen bonds. other state, separated water. Transitions these states occur picosecond nanosecond time scale. When interact interfacial arginine (Arg) lysine (Lys) exhibit considerably different behaviors. Arg show higher propensity rigid contacts nucleotide bases, whereas Lys tend be mobile at molecular interfaces. may facilitate adaptive recognition play both thermodynamic kinetic roles interactions.