Energy Analysis of Zn Polycoordination in a Metalloprotein Environment and of the Role of a Neighboring Aromatic Residue. What Is the Impact of Polarization?

International audienc

Synthesis and evaluation of non-hydrolyzable d-mannose 6-phosphate surrogates reveal 6-deoxy-6-dicarboxymethyl-d-mannose as a new strong inhibitor of phosphomannose isomerases

International audienc

Polarizable Water Networks in Ligand–Metalloprotein Recognition. Impact on the Relative Complexation Energies of Zn-Dependent Phosphomannose Isomerase with d -Mannose 6-Phosphate Surrogates

International audienc

The reaction mechanism of type I phosphomannose isomerases: New information from inhibition and polarizable molecular mechanics studies

International audienc

Conformational analysis of a polyconjugated protein-binding ligand by joint quantum chemistry and polarizable molecular mechanics. Addressing the issues of anisotropy, conjugation, polarization, and multipole transferability

International audienc

Addressing the issues of non-isotropy and non-additivity in the development of quantum chemistry-grounded polarizable molecular mechanics.

International audienceWe review two essential features of the intermolecular interaction energies (ΔE) computed in the context of quantum chemistry (QC): non-isotropy and non-additivity. Energy-decomposition analyses show the extent to which each comes into play in the separate ΔE contributions, namely electrostatic, short-range repulsion, polarization, charge-transfer and dispersion. Such contributions have their counterparts in anisotropic, polarizable molecular mechanics (APMM), and each of these should display the same features as in QC. We review examples to evaluate the performances of APMM in this respect. They bear on the complexes of one or several ligands with metal cations, and on multiply H-bonded complexes. We also comment on the involvement of polarization, a key contributor to non-additivity, in the issues of multipole transferability and conjugation. In the last section we provide recent examples of APMM validations by QC, which relate to interactions taking place in the recognition sites of kinases and metalloproteins. We conclude by mentioning prospects of extensive applications of APMM

Stacked and H-bonded cytosine dimers. Analysis of the intermolecular interaction energies by parallel quantum chemistry and polarizable molecular mechanics.

International audienceUntil now, atomistic simulations of DNA and RNA and their complexes have been executed using well calibrated but conceptually simple pair-additive empirical potentials (force fields). Although such simulations provided many valuable results, it is well established that simple force fields also introduce errors into the description, underlying the need for development of alternative anisotropic, polarizable molecular mechanics (APMM) potentials. One of the most abundant forces in all kinds of nucleic acids topologies is base stacking. Intra- and interstrand stacking is assumed to be the most essential factor affecting local conformational variations of B-DNA. However, stacking also contributes to formation of all kinds of noncanonical nucleic acids structures, such as quadruplexes or folded RNAs. The present study focuses on 14 stacked cytosine (Cyt) dimers and the doubly H-bonded dimer. We evaluate the extent to which an APMM procedure, SIBFA, could account quantitatively for the results of high-level quantum chemistry (QC) on the total interaction energies, and the individual energy contributions and their nonisotropic behaviors. Good agreements are found at both uncorrelated HF and correlated DFT and CCSD(T) levels. Resorting in SIBFA to distributed QC multipoles and to an explicit representation of the lone pairs is essential to respectively account for the anisotropies of the Coulomb and of the exchange-repulsion QC contributions