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Supramolecular macrocyclic forces have been used to trap phytate,myo‐inositol‐1,2,3,4,5,6‐hexakisphosphate, a key bioanion with multiple roles in metabolic processes. Due to the complex chemistry of six multivalent phosphates surrounding the small, cyclic inositol framework, crystallographic information of simple phytate salts has been elusive. This report represents a combined crystallographic, theoretical, and solution binding investigation of a supramolecular macrocyclic complex of phytate. Together, the results provide significant insight to phytate's intramolecular and intermolecular interactions at the microenvironment level. The macrocycle‐phytate aggregates consist of phytate anionic pairs, each partly sandwiched by two 24‐membered, amide/amine‐based cationic macrocycles. The phytate ion pairs hold the tetrameric macrocyclic array together by six strong intermolecular hydrogen bonds. Both phytates crystallize in 1a5e phosphate conformations (one axial (P2) and five equatorial phosphates). Solution NMR binding studies in 1 : 1 DMSO‐d₆ : D₂O indicate 2 : 1 macrocycle:phytate associations, suggesting that the sandwich‐like nature of the complex holds together in solution. DFT studies indicate the likely occurrence of dynamic intramolecular interchange of phosphate protons, as well as important roles for the axial (P2) phosphate in both intramolecular and intermolecular hydrogen bonding interactions.

 

The self-assembly in aqueous solutions of three quaternary salt-based C 16 -type cationic surfactants with different polar head groups and identical carbon alkyl chain viz. , cetylpyridinium bromide (CPB), cetyltrimethylammonium tosylate (CTAT), and cetyltriphenylphosphonium bromide (CTPPB) in the presence of 1-butanol (BuOH) and 1,4-butanediol (BTD) was investigated using tensiometry, 2D-nuclear Overhauser enhancement spectroscopy (2D-NOESY) and small angle neutron scattering (SANS) techniques. The adsorption parameters and micellar characteristics evaluated at 303.15 K distinctly showed that BuOH promotes the mixed micelle formation while BTD interfered with the micellization phenomenon. The SANS data fitted using an ellipsoid (as derived by Hayter and Penfold using the Ornstein-Zernike equation and the mean spherical approximation) and wormlike micellar models offered an insight into the micelle size/shape and aggregation number ( N agg ) in the examined systems. The evaluated descriptors presented a clear indication of the morphology transition in cationic micelles as induced by the addition of the two alcohols. We also offer an investigation into the acceptable molecular interactions governing the differences in micelle morphologies, using the non-invasive 2D-NOESY technique and molecular modeling. The experimental observations elucidated from computational simulation add novelty to this work. Giving an account to the structural complexity in the three cationic surfactants, the molecular dynamics (MD) simulation was performed for CPB micelles in an aqueous solution of alcohols that highlighted the micelle solvation and structural transition, which is further complemented in terms of critical packing parameter (PP) for the examined systems. 

Biomolecules have been thoroughly investigated in a multitude of solvents historically in order to accentuate or modulate their superlative properties in an array of applications. Ionic liquids have been extensively explored over the last two decades as potential replacements for traditional organic solvents, however, they are sometimes associated with a number of limitations primarily related to cost, convenience, accessibility, and/or sustainability. One potential solvent which is gaining considerable traction in recent years is the so-called deep eutectic solvent which holds a number of striking advantages, including biodegradability, inherently low toxicity, and a facile, low-cost, and solventless preparation from widely available natural feedstocks. In this review, we highlight recent progress and insights into biomolecular behavior within deep eutectic solvent-containing systems, including discussions of their demonstrated utility and prospects for the biostabilization of proteins and nucleic acids, free enzyme and whole-cell biocatalysis, various extraction processes ( e.g. , aqueous biphasic systems, nanosupported separations), drug solubilization, lignocellulose biomass treatment, and targeted therapeutic drug delivery. All indications point to the likelihood that these emerging solvents have the capacity to satisfy the requirements of environmental responsibility while unlocking biomolecular proficiency in established biomedical and biotechnological pursuits as well as a number of academic and industrial ventures not yet explored. 

The enzyme Candida Antarctica lipase B (CALB) serves here as a model for understanding connections among hydration layer dynamics, solvation shell structure, and protein surface structure. The structure and dynamics of water molecules in the hydration layer were characterized for regions of the CALB surface, divided around each α-helix, β-sheet, and loop structure. Heterogeneous hydration dynamics were observed around the surface of the enzyme, in line with spectroscopic observations of other proteins. Regional differences in the structure of the biomolecular hydration layer were found to be concomitant with variations in dynamics. In particular, it was seen that regions of higher density exhibit faster water dynamics. This is analogous to the behavior of bulk water, where dynamics (diffusion coefficients) are connected to water structure (density and tetrahedrality) by excess (or pair) entropy, detailed in the Rosenfeld scaling relationship. Additionally, effects of protein surface topology and hydrophobicity on water structure and dynamics were evaluated using multiregression analysis, showing that topology has a somewhat larger effect on hydration layer structure–dynamics. Concave and hydrophobic protein surfaces favor a less dense and more tetrahedral solvation layer, akin to a more ice-like structure, with slower dynamics. Results show that pairwise entropies of local hydration layers, calculated from regional radial distribution functions, scale logarithmically with local hydration dynamics. Thus, the Rosenfeld relationship describes the heterogeneous structure–dynamics of the hydration layer around the enzyme CALB. These findings raise the question of whether this may be a general principle for understanding the structure–dynamics of biomolecular solvation.