Enhancing the enthalpic contribution of hydrogen bonds by solvent shielding

Abstract

Altering local dielectric properties induced by solvent shielding, enhances polar interactions and leads to enthalpically driven recognition of polar substrates.

Investigating the Impact of Hydrophobic Polymer Segments on the Self-Assembly Behavior of Supramolecular Cyclic Peptide Systems via Asymmetric-Flow Field Flow Fractionation

“…This increase in the enthalpic attraction between the subunits can be correlated to the role of the inner hydrophobic polymer layers in shielding the backbone hydrogen bonding sites from competitive water molecules. In their study on the binding between mannoside ligands and lectin, Cramer et al reported a −13 kJ mol –1 enthalpic contribution that was a direct consequence of H-bond shielding . In contrast, it was found that when the hydrogen bond network in the binding site was disrupted, the enthalpic benefit was completely abolished.…”

“…In contrast, it was found that when the hydrogen bond network in the binding site was disrupted, the enthalpic benefit was completely abolished. Shielding of H-bonds by hydrophobic entities has also been reported to strengthen the H-bonds as they provide low dielectric environments in which dipole–dipole “electrostatic” interactions are stabilized. − Importantly, simulation research by Barril and co-workers suggested that the level of shielding, and hence the influence on enthalpic contributions, is likely proportional to the hydrophobic quantity …”

Structural and biochemical characterization of the relaxosome auxiliary proteins encoded on the Bacillus subtilis plasmid pLS20

“…The ITC results indicate that the interaction was favorable in terms of enthalpy and entropy, with a calculated ΔG 0 of −6180.92 kJ mol −1 , mainly driven by the exothermic component of the binding, with a ΔH 0 of −5722 ± 120.4 kJ mol −1 and a ΔS 0 of 1.54 kJ mol −1 . Both parameters suggest that the interaction between Aux1 pLS20 and Rel pLS20 is strongly affected by hydrogen bond formation and van der Waals interactions [49] . The entropy component, although small, may be related to the burial of water-accessible surface area upon binding, resulting in the release of interfacial water molecules to the solvent, contributing favorably to the total entropy of interaction [50] .…”

Preparation and DFT Study for New Three-Ring Supramolecular H-Bonded Induced Liquid Crystal Complexes

“…Differential scanning calorimetry (DSC) results of liquid crystals even for those produced through supramolecular assemblies usually possess relatively high enthalpy changes (ΔH) accompanied with the crystalline mesomorphic transitions (∼20-100 kJ/mol) (Tsuji et al, 1979) (Yousif and Al-Hamdani, 1993) (Domalski and Hearing, 1996) Morsy, 1999) (2000) (Chidichimo et al, 2004) (Acree and Chickos, 2006). However, few examples have been reported in the literature where the ΔH values of melting are lower than 10 kJ/mol (Du et al, 2019) (Cramer et al, 2020) (Huang et al, 2020) (Wang et al, 2020).…”