Polarization functions are taken partly from previous work, partly optimized in atomic MP2 calculations, and for a few cases determined at the HF level for excited atomic states nearly degenerate with the ground state. As opposed to other quadruple zeta basis sets, the basis set errors in atomic ground-state HF energies are less than 1 mEh and increase smoothly across the Periodic Table, while the number of primitives is comparably small. Contraction coefficients and orbital exponents are fully optimized in atomic Hartree-Fock (HF) calculations. This extends earlier work on segmented contracted split valence (SV) and triple zeta valence (TZV) basis sets. We present Gaussian basis sets of quadruple zeta valence quality with a segmented contraction scheme for atoms H to Kr. The matrix-assisted laser desorption/ionization time of the flight mass spectrometry (MALDI-TOF MS) of H6EB is also reported of manner to enrich the knowledge about its reactivity. The dependence of electrostatic potential and frontier orbitals with the catecholamide dihedral angles of H6EB is described. The good agreement between the experimental and the calculated spectra using LC-PBE/QZVP and ultrafine grid suggest the possibility of the systems reported here to be considered as a standard set. Calculated1H and13C NMR spectra enable the effect of the solvent to be understood in the context of the experimental measurements. The NMR DFT calculations show a strong dependence on the xc functional, basis set, and grid used for the H6EB structure. The results show a significant difference between the OH and NH bands, while the CO amide and O(CO) IR bands are often found on top of each other. We used two exchange-correlation (xc) functionals (PBE including long-range corrections LC-PBE and mPW1), 2 basis sets (QZVP and 6-31G(d)) and 2 grids (fine and ultrafine) for most of the H6EB structures dependent of dihedral angles. In order to facilitate the elucidation of enterobactin and its analogues, here we propose the creation of a H6EB standard set using Density Functional Theory Infrared (IR) and NMR spectra. As it is known, Enterobactin (H6EB) is an efficient iron carrier synthesized and secreted by many microbial species. Currently, Enterobactin and Enterobactin derivatives have gained interest, owing to their potential application in the pharmaceutical field. This work is expected to enrich our knowledge on the folding equilibria of Ent enantiomers and their An3+/4+-Ent complexes, and contribute to communities that concern the in vivo and in vitro behaviors of Ent enantiomers and actinides.Įmerging and re-emerging epidemic diseases pose an ongoing threat to global health. The Fe³⁺-Ent complexes constructed a more compact conformation, while the relatively loosely bound An3+/4+-Ent complexes allowed solvent water molecules to access the first coordination shell of An3+/4+ and weakened the interaction between An3+/4+ and Ent. The conformational analysis and the energy decomposition of M3+/4+-Ent complexes indicated that their distinct conformational variations and dynamic fluxionality are enthalpy driven behaviors and dependent on the nature of the loaded metal ions. Upon binding with metal ions, the dynamics of Ent enantiomers exhibited dependence on the metal ions, and appeared to be more flexible in An3+/4+-Ent complexes than in Fe³⁺-Ent complexes. Helicity preference was observed in the folded states of Ent enantiomers, which was solidified when binding with Fe³⁺ while disrupted when binding with actinides. In their neutral state, both enantiomers may exist in their folded and extended states in aqueous phase with the former more stable owing to the favorable cation-π, π-π, and H-bond interactions. For comparison, ferric cation was also considered. Here, we report molecular dynamics simulations of both Ent enantiomers and their complexes with key actinides (Am³⁺, Cm³⁺, Th⁴⁺, U⁴⁺, Np⁴⁺, Pu⁴⁺) to study the folding equilibria of Ent enantiomers and their binding affinity with actinide. Its dynamics in its intact form and holo state remain to study to understand its role in in vivo behavior of metal ions and to facilitate its potential application in drug design and environmental remediation. Enterobactin (Ent) is a typical siderophore with strong iron affinity.
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