Proton Transfers to DNA in Native Electrospray Ionization Mass Spectrometry: A Quantum Mechanics/Molecular Mechanics Study.

ABSTRACT: Native electrospray ionization-ion mobility mass spectrometry (N-ESI/IM-MS) is a powerful approach for low-resolution structural studies of DNAs in the free state and in complex with ligands. Solvent vaporization is coupled with proton transfers from ammonium ions to the DNA, resulting in a reduction of the DNA charge. Here we provide insight into these processes by classical molecular dynamics and quantum mechanics/molecular mechanics free energy calculations on the d(GpCpGpApApGpC) heptamer, for which a wealth of experiments is available. Our multiscale simulations, consistent with experimental data, reveal a highly complex scenario. The proton either sits on one of the molecules or is fully delocalized on both, depending on the level of hydration of the analytes and the size of the drop

SUBMITTER: Paulikat M 

PROVIDER: S-EPMC9806827 | biostudies-literature | 2022 Dec

REPOSITORIES: biostudies-literature