Intermolecular Structure Research Articles

The iMab antibody selectively binds to intramolecular and intermolecular i-motif structures.

i-Motifs (iMs) are quadruplex nucleic acid conformations that form in cytosine-rich regions. Because of their acidic pH dependence, iMs were thought to form only in vitro. The recent development of an iM-selective antibody, iMab, has allowed iM detection in cells, which revealed their presence at gene promoters and their cell cycle dependence. However, recent evidence emerged which appeared to suggest that iMab recognizes C-rich sequences regardless of their iM conformation. To further investigate the selectivity of iMab, we examined the binding of iMab to C-rich sequences, using a combination of pull-down and western blot assays. Here, we observe that the composition of buffers used during binding and washing steps strongly influences the selectivity of antibody binding. In addition, we demonstrate by nuclear magnetic resonance that several of the previously reported C-rich sequences, which were not expected to form iMs, actually form intermolecular iMs which are selectively recognized by iMab. Our results highlight the specificity of the iMab antibody, emphasize the importance of avoiding in vitro artifacts by optimizing DNA concentrations, blocking and washing conditions, and confirm thatiMab is selectivenot only for intramolecular iMs but also for intermolecular iMs,whilenot affecting theiM conformation.

Adsorption-biased characterization of porous solids

AbstractThis article summarizes opening address in 9th Characterization of Porous Materials (CPM9). The role and historical sketch of main adsorption-based conferences such as Fundamentals of Adsorption (FOA), Characterization of Porous Solids (COPS), Pacific Basin Conference on Adsorption Science and Technology (PBAST), and Characterization of Porous Materials (CPM) are given. The unique role of CPM in adsorption-based characterization of porous materials is introduced in the above conferences. The concerted stimulation between innovated well-defined nanoporous materials and modernized adsorption studies supported by new theoretical and experimental approaches have given rise to quite active research activities mentioned above. The brief research activities of author’s group, which have aimed to bridge experimental and theoretical studies, are described; they have introduced in-situ X-ray diffraction, in-situ small angle X-ray scattering, high resolution adsorption measurement even from ultrahigh vacuum range, wide-temperature range in-situ IR spectroscopy for elucidation of the intermolecular structure of molecules adsorbed in nanopores. Also, future scope of the research on characterization of porous solids is proposed.

Experimental determination of deviation from spherical electron densities of atoms in cyclohexane molecules in the liquid state

Abstract Deviation from the spherical electron distribution of atoms in liquid cyclohexane has been determined through the difference interference term between the observed x-ray intermolecular interference term and the sum of the intermolecular partial structure factors weighted by x-ray atomic scattering factors. The difference distribution function indicates a broadened negative peak at r ∼ 3.7 Å, suggesting that the electron density decreases in the radial distance that corresponds to the intermolecular distances of neighboring cyclohexane molecules.

Loosening the Solvation Cage in Polysaccharide Polymer Electrolyte for Sustainable Lithium Metal Batteries.

Biomass with naturally ion-conducting segments (e.g., hydroxyl) holds promise for sustainable batteries. Several expeditions are proposed to successfully enhance the ion conduction in biomass polymer mainly by intermolecular structure regulation. Presently, the recognition and research of biomass polymer electrolytes are still limited, requiring continuous explorations to promote the application of such promising electrolytes. Herein, a molecularly asymmetric electrolyte is produced, comprising polysaccharides of starch and chitosan. The strong Li+-O (hydroxyl) interactions are replaced by weak Li+-oxygen (O) of ester carbonyl, and the steric hindrance group -NH3 + promotes the immobilization of anion and stabilization of the interface. Such intermolecular chemical modulations of biomass are achieved by a one-pot esterification and protonation of polysaccharides. A loosely-solvating cage structure with the participation of O of ester carbonyl, glycerol, and anion, allowing the rapid conduction (1.82 × 10-4 S cm-1 at 30 °C) and a high migration number (0.49) of Li+. Moreover, Li symmetric cells (2500h) and Li4TiO5 | Li cells (400 cycles) employing the SCA electrolyte show superior cycling stability. The polysaccharide BPEs and solvation regulation strategy open up a promising avenue for constructing sustainable batteries.

Influence of charge on conformations, inter-molecular structure and thermodynamics of symmetric polystyrene-block-polymethacrylic acid (PS-b-PMA) polyelectrolyte micelle in aqueous solution

ABSTRACT The various aspects of molecular structure, kinetics, and thermodynamics of symmetric polystyrene-b-poly(methacrylic acid) (PS-b-PMA) block copolymer micelle in salt-free aqueous solution as a function of degree-of-ionisation (f) of PMA (corona) block was investigated by explicit molecular dynamics (MD) simulations. Micelle size increases linearly with f in a qualitative agreement with simulation results in the literature. With increase in charge density of the corona-forming PMA chain block, the micelle becomes more spherical, and there is a decrease in the surface area of micelle core and an increase in the favourable interactions among the PS chains. The structure of the micelle changes with f. The behaviour of the RDF’s of core and corona PMA atoms and the enthalpy of solvation show that the interactions among the segments of the core PS blocks are insensitive to variation in f. The atom density profiles, solvation enthalpy, and coordination number of PMA-Na+ and Water-Na+ pairs reveal the existence of the micelle in the ‘osmotic regime’ in agreement with results from experiments and mean-field theory in literature. The significance of electrostatic interactions on the kinetics of formation, structural aspects, and thermodynamics of micellisation is shown. The characteristics of PMA-b-PS micelle are compared with those of PAA-b-PS.

Insight Into Factors Influencing the Aggregation Process in Wild-Type and P66R Mutant SOD1: Computational andSpectroscopic Approaches.

Disturbances in metal ion homeostasis associated with amyotrophic lateral sclerosis (ALS) have been described for several years, but the exact mechanism of involvement is not well understood. To elucidate the role of metalation in superoxide dismutase (SOD1) misfolding and aggregation, we comprehensively characterized the structural features (apo/holo forms) of WT-SOD1 and P66R mutant in loop IV. Using computational and experimental methodologies, we assessed the physicochemical properties of these variants and their correlation with protein aggregation at the molecular level. Modifications in apo-SOD1 compared to holo-SOD1 were more pronounced in flexibility, stability, hydrophobicity, and intramolecular interactions, as indicated by molecular dynamics simulations. The enzymatic activities of holo/apo-WT SOD1 were 1.30 and 1.88-fold of the holo/apo P66R mutant, respectively. Under amyloid-inducing conditions, decreased ANS fluorescence intensity in the apo-form relative to the holo-form suggested pre-fibrillar species and amyloid aggregate growth due to occluded hydrophobic pockets. FTIR spectroscopy revealed that apo-WT-SOD1 and apo-P66R exhibited a mixture of parallel and intermolecular β-sheet structures, indicative of aggregation propensity. Aggregate species were identified using TEM, Congo red staining, and ThT/ANS fluorescence spectroscopy. Thermodynamic analyses with GdnHCl demonstrated that metal deficit, mutation, and intramolecular disulfide bond reduction are essential for initiating SOD1 misfolding and aggregation. These disruptions destabilize the dimer-monomer equilibrium, promoting dimer dissociation into monomers and decreasing the thermodynamic stability of SOD1 variants, thus facilitating amyloid/amorphous aggregate formation. Our findings offer novel insights into protein aggregation mechanisms in disease pathology and highlight potential therapeutic strategies against toxic protein aggregation, including SOD1.

(Invited) Designing Redox-Active Organic Molecules (ROMs) for Fast-Charging Battery Electrodes with High Stability

Redox-active organic molecules (ROMs) are drawing significant attention as promising alternatives to conventional transition metal oxide electrodes. Their appeal stems from numerous benefits including abundance, sustainability, biocompatibility, cost-effectiveness, and ease of chemical tunability. Notably, their flexible nature with large free volume, owing to loosely packed intermolecular structures, is expected to facilitate fast diffusion of charge-carrying ions – a key attribute for enhancing the high-rate performance of electrode materials. Yet, the practical application of ROMs is hindered by their slow rate capability with limited capacity utilization, a consequence of their intrinsically electron insulating properties. Furthermore, the high solubility of ROMs in organic electrolytes has caused rapid capacity fading within the first few cycles, compelling one to prepare polymers via complicated synthesis and/or to fabricate composites with expensive nanocarbons. These factors increase production costs and significantly deteriorate processability in the electrode fabrication process.In this talk, we introduce novel molecular design strategies to improve both cycle stability and rate performance in simple small molecule ROMs, paving the way for the development of fast charging batteries.

Synthesis, Structural Aspects, Magnetic, and Adsorption Properties of a Dinuclear Cu (II) Complex Derived From Mixed Ligand Approach

ABSTRACTA dinuclear copper complex, [Cu2(teaH)(pNBA)2(H2O)2]·MeOH·pNBH (1) (where teaH3 = triethanolamine, pNBH = 4‐nitro‐benzoic acid, and pNBA = 4‐nitro‐benzoate) has been prepared and structurally characterized. In 1, there is an interesting intermolecular structure that is shown as a tetramer copper connected in chain‐like motif. In the UV‐Vis spectrum, higher absorbance at 267 nm is referred to n → π* transition, coupled with a weak peak at 500 nm, indicating another transition, which is specified as metal‐to‐ligand charge transfer. The higher intensity peak in the photoluminescence spectrum is marked as the absorption of energy required for the excitation of electrons, whereas lower intensity peaks show the emission of energy, which describes d‐d transitions of Cu (II) electrons due to d9 configuration. Complex 1 was explored for the adsorption of methylene blue (MB) dye, with the maximum adsorption as 101.07 mg/g, whereas the removal efficiency was estimated to be 81.05%. In conformity with the kinetic studies, the adsorption process proceeded via a Pseudo‐first‐order kinetic model. The incorporation of mixed ligands such as teaH3 and pNBH in 1 tends to increase the dimensionality that led to increased MB adsorption. The plausible mechanism behind the adsorption was favored by hydrogen‐bonding, electrostatic, π–π, and n–π* interactions, operating between the dye and complex 1. Further, the H‐bonding and these interactions provided stability to the complex, and an improved dye adsorption was observed even during the 2nd and 3rd recyclability experiments. Additionally, complex 1 corroborated remarkable stability after dye adsorption, allowing for up to four recycling turns. The magnetic study revealed antiferromagnetic coupling between the two magnetic centers with a singlet ground state (S = 0).

Unravelling the Complexity of Amyloid Peptide Core Interfaces.

Amyloids, large intermolecular sandwiched β-sheet structures, underlie several protein misfolding diseases but have also been shown to have functional roles and can be a basis for designing smart and responsive nanomaterials. Short segments of proteins, called aggregation-prone regions (APRs), have been identified that nucleate amyloid formation. Here we present the database of 173 APR crystal structures currently available in the PDB, and a tool, ACW, for analyzing their topologies and the 267 inter-β-sheet interfaces of zipper regions assigned in these structures. We defined a new descriptor of zipper interfaces, the surface detail index (SDi), which quantifies the intertwining between the side chains of both β-sheets of the zipper, an important factor for the molecular recognition and self-assembly of these mesostructures. This allowed a comparative analysis of the zipper interfaces and identification of 6 clusters with different intertwining, steric fit, and size characteristics using three complementary descriptors, SDi, shape complementarity, and buried surface area. 60% of the APR structures are formed by parallel β-sheets, of which 52% belong to the topological class 1. This could be explained by the better fit and a deeper entanglement of the zipper regions of the parallel structures than of the antiparallel structures, as the analysis showed that both their shape complementarity (0.79 vs 0.70) and SDi (1.53 vs 1.32) were higher. The higher abundance of certain residues (Asn and Gln in parallel and Leu and Ala in antiparallel β-sheets) can be explained by their ability to form different ladder-like secondary interaction patterns within β-sheets. Analogous to the hierarchy of protein structure, we interpreted the primary, secondary, tertiary, and quaternary structure levels of APRs revealing different characteristics of the zipper regions for both parallel and antiparallel β-sheet structures, which may provide clues to the structural conditions of amyloid core formation and the rational design of amyloid polymorphs.

Komplexer Tanz von Molekülen am Himmel: Choreographie der intermolekularen Struktur und Dynamik im heteroternären Cluster Cyclopenten−CO2−H2O

AbstractDiese Studie untersucht die treibenden Kräfte hinter der Bildung eines heteroternären Clusters, der aus flüchtigen organischen Verbindungen industrieller Herkunft oder Verbrennungsquellen, insbesondere Cyclopenten, neben Treibhausgasen wie Kohlendioxid und Wasserdampf besteht. Obwohl beim Verständnis binärer Komplexe erhebliche Fortschritte erzielt wurden, sind die strukturellen Feinheiten heteroternärer Cluster weitgehend unerforscht. Unsere Studie charakterisiert den heteroternären Cyclopenten−CO2−H2O‐Cluster mithilfe der Fourier‐Transformations‐Mikrowellenspektroskopie. Im gepulsten Strahl wird ein Isomer beobachtet, in dem sich CO2 und H2O über dem Cyclopentenring ausrichten, wobei Wasser eine interne Rotation um seine C2‐Symmetrieachse vollführt. Theoretische Analysen stützen diese Beobachtungen und identifizieren eine O−H⋅⋅⋅π‐Wasserstoffbrücke und eine sekundäre C⋅⋅⋅O‐Tetrelbindung innerhalb des Clusters. Diese Studie stellt einen entscheidenden Schritt zum Verständnis der molekularen Dynamik und Wechselwirkungen von VOCs, Treibhausgasen und Wasser in der Atmosphäre dar und ebnet den Weg für weitere Untersuchungen ihrer Rollen in der Klimadynamik und Luftqualität.

Complex Dance of Molecules in the Sky: Choreography of Intermolecular Structure and Dynamics in the Cyclopentene-CO2-H2O Hetero Ternary Cluster.

This study delves into driving forces behind the formation of a hetero ternary cluster consisting of volatile organic compounds from industrial or combustion sources, specifically cyclopentene, alongside greenhouse gases like carbon dioxide, and water vapor. While substantial progress has been made in understanding binary complexes, the structural intricacies of hetero ternary clusters remain largely uncharted. Our research characterized the cyclopentene-CO2-H2O hetero ternary cluster utilizing Fourier transform microwave spectroscopy. The observed isomer in the pulsed jet has CO2 and H2O aligning above the cyclopentene ring, with water undergoing an internal rotation approximately about its C2 symmetry axis. Theoretical analyses support these observations, identifying an O-H⋅⋅⋅π hydrogen bond and a secondary C⋅⋅⋅O tetrel bond within this cluster. This study marks a critical step towards comprehending the molecular dynamics and interactions of VOCs, greenhouse gases, and water in the atmosphere, paving the way for further investigations into their roles in climate dynamics and air quality.

Process-induced protein aggregates influenced pea globulins’ structure formation upon heating

Pea protein ingredients play key role in formulations of plant-based foods. However, functional properties of pea ingredients are inconsistent depending on extraction process. Protein aggregation occurs simultaneously during protein extraction, thus examining the protein aggregated states as induced by processing is essential for better process design. This study investigated the influence of process-induced protein aggregated states on structure formation upon heating of pea protein ingredients. Combining rheological, spectroscopic, and microscopic techniques, the mechanisms underlining heat-induced structure formation have been unveiled from microscopic to macroscopic scales. The salt-extracted isolate (PPI*) where protein aggregation was minimized, developed mesh-like structure through intermolecular protein-protein interaction upon gelling similar to commercial protein concentrate (PPC). In turn, commercial isolate (PPI) as appeared as microscopic particles, formed gel through accumulation of protein particles with no structure development. The aggregated states of PPI* and PPI seemed to dictate vicilin and legumin purification by means of anion exchange chromatography. Purification process promoted intermolecular protein aggregate structures. However, these purified fractions regardless of parent isolates showed similar structure development as PPC and PPI* during gelling. Monitoring protein aggregation during extraction process can be a key to limit functional property variation in pea protein ingredients.

The study of thermodynamic properties of diethylene glycol monoethyl ether with 2-alkanols (C3 − C7) with use of PFP and ERAS modeling

Thermodynamic properties like excess volume VmE, excess partial volume V¯m,iE, in isentropic compressibility deviations Δ Ks, and refractive index deviations ΔnD, have been calculated based on experimental density ρ, speed of sound u, and refractive index nD, by an Anton Paar / DSA 5000/ densimeter and Anton Paar Abbemat / 500/ refractometer. The systems of diethylene glycol monoethyl ether (DEGEE) + 2-propanol, or + 2-butanol, or + 2-pentanol, or + 2-hexanol, or + 2-heptanol, were given at T = (298.15–318.15) in 10 K intervals at ambient pressure (81.5 kPa) have been investigated. Data was fitted by Redlich-Kister relation.TheVmE is negative for + 2-propanol and positive sign for other systems observed. The Δ Ks is negative for all systems, except for + 2-heptanol system is positive. The ΔnD is negative for + 2-hexanol or + 2-heptanol systems and is positive for all the rest. The The intermolecular interactions and structure factors were discussed for the binary mixtures. In addition the Prigogine–Flory–Patterson theory (PFP) and Extended Real Associated Solutions (ERAS) models were used to correlate VmE data of binary mixtures. The fitting data for all systems reasonable consistency with experimental data for all the systems.

Size dependence of transport coefficients of thin and long asphaltene molecules as determined using a mode-coupling theory approach

Rotational diffusion coefficients (Dr) and viscosities (η) of rigid rod molecules consisting of N beads were first revisited for the situation at low density. Starting from this, the transport coefficients at high density condition were expressed in terms of different density pair correlation functions, such as intermolecular radial distribution function and structure factor. This was attained using a mode-coupling theory approach to approximate the intermolecular force–force correlation function, and thus the friction coefficient. As these density pair correlation functions are dependent on N, they determine how “entangled” the rigid rod molecules are, and therefore reproducing the crossover in the log –log plot of transport coefficients with N. It was found that there are crossovers in transport coefficients from Dr∼N−2.3 and η∼N2.3 at low N to Dr∼N−6.5 and η∼N6.5 at high N. The strength of N dependence is mainly determined by the competition between available free space and the compressibility of the system.

Molecular simulations of understanding the Zn2+ ion structure, dynamics and thermodynamic properties in water in ionic liquids

We utilize all-atom molecular dynamics simulations to explore the intermolecular structure, dynamics and thermodynamic properties of Zn2+ ions in water-in-ionic liquid. Two ionic liquid systems featuring the same cation 1-ethyl-3-methyl-imidazolium [EMIM]+ and distinct anions tetrafluoroborate [BF4]− and hexafluorophosphate [PF6]− are considered. We consider the water (H2O) mole fractions (x) varying from 0.33 to 0.71. We observe a significant interactions of Zn2+ ions with water in the case of [BF4]− when compared to [PF6]−. On the other hand Zn2+ ions mobility rises more in [EMIM]+[BF4]− as compared to [EMIM]+[PF6]− with x. Higher self-diffusion (D) of Zn2+ ions is seen in the case of [EMIM]+[BF4]−. The ionic conductivity (σ) of [EMIM]+[BF4]− is greater compared to [EMIM]+[PF6]− with the rise in x. Overall, this article furnishes in-depth molecular-level insights into the behaviour of Zn2+ ions in the presence of water mixed ionic liquid electrolytes.

Molecular simulation of understanding the structure and separation thermodynamics of BTX (Benzene, Toluene, Xylene) using amino acid based ionic liquids

The separation of aromatics and aliphatic from the hydrocarbon mixture stands a significant challenge. In this manuscript we present atomistic molecular dynamic simulations to understand the structure and separation thermodynamic properties of BTX (Benzene, toluene, xylene) from n-heptane using ionic liquids. Here we considered the amino acid derived ionic liquid considering the tetra butyl phosphonium as cation and valine anion at three different temperatures 298 K, 323 K and 348 K. We observe that IL show strong intermolecular structure with BEN (benzene) when compared to TOL (toluene) and XYL (p-xylene). Based on the solvation free energy (ΔGsolv), transfer free energy (ΔGtransfer) and partition coefficient (log P) analysis of BEN show favourable for the transfer from n-heptane to IL phase when compared to TOL and XYL. Overall results presented in this paper provide molecular level understanding of the design of amino acid-based IL for the separation BTX from the hydrocarbon mixture.

Why Is Arginine the Only Amino Acid That Inhibits Polyglutamine Monomers from Taking on Toxic Conformations?

Polyglutamine (polyQ) diseases are devastating neurodegenerative disorders characterized by abnormal expansion of glutamine repeats within specific proteins. The aggregation of polyQ proteins is a critical pathological hallmark of these diseases. Arginine was identified as a promising inhibitory compound because it prevents polyQ-protein monomers from forming intra- and intermolecular β-sheet structures and hinders polyQ proteins from aggregating to form oligomers. Such an aggregation inhibitory effect was not observed in other amino acids. However, the underlying molecular mechanism of the aggregation inhibition and the factors that differentiate arginine from other amino acids, in terms of the inhibition of the polyQ-protein aggregation, remain poorly understood. Here, we performed replica-permutation molecular dynamics simulations to elucidate the molecular mechanism by which arginine inhibits the formation of the intramolecular β-sheet structure of a polyQ monomer. We found that the intramolecular β-sheet structure with more than four β-bridges of the polyQ monomer with arginine is more unstable than without any ligand and with lysine. We also found that arginine has 1.6-2.1 times more contact with polyQ than lysine. In addition, we revealed that arginine forms more hydrogen bonds with the main chain of the polyQ monomer than lysine. More hydrogen bonds formed between arginine and polyQ inhibit polyQ from forming the long intramolecular β-sheet structure. It is known that intramolecular β-sheet structure enhances intermolecular β-sheet structure between proteins. These effects are thought to be the reason for the inhibition of polyQ aggregation. This study provides insights into the molecular events underlying arginine's inhibition of polyQ-protein aggregation.

High-Performance Supercapacitor Electrodes from Fully Biomass-Based Polybenzoxazine Aerogels with Porous Carbon Structure.

In recent years, polybenzoxazine aerogels have emerged as promising materials for various applications. However, their full potential has been hindered by the prevalent use of hazardous solvents during the preparation process, which poses significant environmental and safety concerns. In light of this, there is a pressing need to explore alternative methods that can mitigate these issues and propel the practical utilization of polybenzoxazine aerogels. To address this challenge, a novel approach involving the synthesis of heteroatom self-doped mesoporous carbon from polybenzoxazine has been devised. This process utilizes eugenol, stearyl amine, and formaldehyde to create the polybenzoxazine precursor, which is subsequently treated with ethanol as a safer solvent. Notably, the incorporation of boric acid in this method serves a dual purpose: it not only facilitates microstructural regulation but also reinforces the backbone strength of the material through the formation of intermolecular bridged structures between polybenzoxazine chains. Moreover, this approach allows ambient pressure drying, further enhancing its practicability and environmental friendliness. The resultant carbon materials, designated as ESC-N and ESC-G, exhibit distinct characteristics. ESC-N, derived from calcination, possesses a surface area of 289 m2 g-1, while ESC-G, derived from the aerogel, boasts a significantly higher surface area of 673 m2 g-1. Furthermore, ESC-G features a pore size distribution ranging from 5 to 25 nm, rendering it well suited for electrochemical applications such as supercapacitors. In terms of electrochemical performance, ESC-G demonstrates exceptional potential. With a specific capacitance of 151 F g-1 at a current density of 0.5 A g-1, it exhibits superior energy storage capabilities compared with ESC-N. Additionally, ESC-G displayed a more pronounced rectangular shape in its cyclic voltammogram at a low voltage scanning rate of 20 mV s-1, indicative of enhanced electrochemical reversibility. The impedance spectra of both carbon types corroborated these findings, further validating the superior performance of ESC-G. Furthermore, ESC-G exhibits excellent cycling stability, retaining its electrochemical properties even after 5000 continuous charge-discharge cycles. This robustness underscores its suitability for long-term applications in supercapacitors, reaffirming the viability of heteroatom-doped polybenzoxazine aerogels as a sustainable alternative to traditional carbon materials.

Effects of heat‐moisture treatment on the multiscale structure and digestibility of sweet potato starch

SummaryThe effects of water content on the multi‐scale structure and digestibility of sweet potato starch (SPS) during heat‐moisture treatment (HMT) were studied, and the relationship between water content, starch structure and starch digestibility was analysed. The results showed that the surface of SPS granules changed after HMT, mainly in the form of depression, rupture and adhesion, and the change was more obvious with the increase of water content, and the crystalline structure changed from the original A‐type to A + V‐type. The relative crystallinity and double helix content decreased, the thickness of semi‐crystalline layered structure increased, and the peak intensity decreased. The molecular weight of SPS after HMT tended to be distributed in the low molecular weight range of 4 × 104 g mol−1 < Mw <4 × 105 g mol−1. These structural changes promoted the rearrangement of the intermolecular structure of SPS, which made amylase shield the original action site when acting on SPS, and converted part of rapidly digestible starch (RDS) content into slow digestible starch (SDS) and resistant starch (RS) content, resulting in the increase of SDS and RS content. Especially in HMT‐25, the RS content of SPS was the highest, which was 28.60%. The experimental data can provide theoretical support for broadening the application of SPS.

Peculiarities of the Dynamical Hydration Shell of Native Conformation Protein Using a Bovine Serum Albumin Example.

This paper describes an approach based on the method of terahertz time-domain spectroscopy, which allows the analysis of dynamical hydration shells of proteins with a thickness of 1-2 nm. Using the example of bovine serum albumin in three conformations, it is shown that the hydration shells of the protein are characterized by increased binding of water molecules in the primary hydration layers, and in more distant areas of hydration, on the contrary, the water structure is somewhat destroyed. The fraction of free or weakly bound molecules, usually observed in the structure of liquid water in hydration shells, become more numerous but its average binding is greater than in undisturbed water. The energy distribution of hydrogen bonds in hydration shells is narrowed compared to undisturbed water. All these manifestations of hydration are most pronounced for the native conformation of the protein. Also, the hydration shells of the native protein are characterized by a smaller number of hydrogen bonds and a tendency to decrease their average energy compared to non-native conformations. The fact of a pronounced peculiarity of the hydration shells of the protein in the native conformation has been noted for different proteins before. However, the methodological approach used in this work for the first time allowed this peculiarity to be described by specific parameters of the intermolecular structure and dynamics of water.