Disulfonic Acid Research Articles

Electroacupuncture may alleviate inflammatory pain by downregulating the expression of P2Y14 receptor in the primary somatosensory cortex.

Increasing evidence indicated that purinergic signalling involved in electroacupuncture (EA)-induced analgesia. Whether purinergic P2Y14 receptor contributes to EA-mediated analgesia remains unclear. Here, we report that the expression of P2Y14 receptor in the hindlimb region of the primary somatosensory cortex (S1HL) was significantly upregulated on Complete Freund's Adjuvant (CFA)-induced pain model mice, while was downregulated after EA treatment (2Hz frequency, 1mA intensity, and 30min duration) at "Zusanli" (also named ST36 acupoint). EA-mediated analgesia could be reversed by injection of P2RY14 agonist uridine diphosphate glucose (UDPG) into the bilateral S1HL, while prolonged by injection of P2RY14 antagonist pyridoxal phosphate-6-azophenyl-2',4'-disulfonic acid (PPTN). It suggested that EA may alleviate inflammatory pain by downregulating the expression of P2RY14 in the S1HL.

Genome-wide CRISPR screens identify CLC-2 as a drug target for anti-herpesvirus therapy: tackling herpesvirus drug resistance.

The emergence of drug resistance to virus (i.e., acyclovir (ACV) to herpesviruses) has been termed one of the common clinical issues, emphasizing the discovery of new antiviral agents. To address it, a genome-wide clustered regularly interspaced short palindromic repeats (CRISPR) screening was performed in mouse haploid embryonic stem cells infected with pseudorabies virus (PRV), an α-herpesvirus causing human and pig diseases. The results demonstrated that type 2 voltage-gated chloride channels (CLC-2) encoded by one of the identified genes, CLCN2, is a potential drug target for anti-herpesvirus therapy. CLC-2 inhibitors, omeprazole (OME) and 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS), can efficiently inhibit infection of multiple herpesviruses in cellulo (i.e., PRV, HSV and EBV), and effectively treat murine herpes simplex encephalitis (HSE). Additionally, DIDS was found to inhibit HSV-1 replication by blocking the PI3K/Akt pathway. Most importantly, both DIDS and OME were able to inhibit ACV-resistant HSV-1 strain infection. The study's findings suggest that targeting host-cell factors such as CLC-2 may be a promising approach to tackling herpesvirus drug resistance. The discovery of CLC-2 as a potential drug target for anti-herpesvirus therapy provides a new direction for the development of novel antiviral agents.

Optimation of Fe3+ Ion Desorption Using Sulfonate Modified Silica Gel-GPTMS

Silica gel is one of the adsorbents widely used in adsorption, but silica gel has a low ability to absorb metals. Hence, modifications need to be made to improve it. Silica gel modified using sulfonate groups from monosodium salt compound of 4-amino-5-hydroxy-2,7-naphthalene disulfonic acid using GPTMS coupling compound for adsorption and desorption of Fe3+ ions by column method was carried out. The adsorption process of Fe3+ ions using silica gel-GPTMS-sulfonate has been carried out in previous studies and obtained an optimum state at pH 6 and a concentration of 20 ppm. After the adsorption process is carried out, the desorption process is continued with variations in the type of desorption eluent and concentration variations. The types of desorption agents are NaCl, CaCl2, HCl, and HNO3, with the optimum desorption agent being HNO3 with a release of 0.077517 mg of Fe3+ ions from 0.1587403 mg of Fe3+ ions absorbed and a desorption percentage of 48.83%. The concentration variations are 0.5 M, 1 M, 2.5 M, and 5 M, with an optimum concentration of 2.5 M HNO3 with a release of 0.098505 mg Fe3+ ions and a desorption percentage of 64.43%.

Syntheses and antimicrobial activities of two coordination polymers assembled with Ag[sbnd]N and Ag[sbnd]O bonds

Two new coordination polymers ({[Ag(p-phda)2](BF4)} n (1) and {[Ag2(1,5-nds)(DMSO)2] DMSO}n (2) (p-phda: p-phenyldiacetonitrile, 1,5-nds: 1,5-naphthalene disulfonic acid, DMSO: dimethyl sulfoxide) were synthesized and characterized by IR, EA,TG and X-ray single crystal diffraction. 1 was revealed as a 2D “fishing net” assembled by AgN bonds with BF4− as equilibrium charge. IR and PXRD analysis showed the BF4− can be irreversibly exchanged by six anions varied in atomic numbers, sizes, configurations and coordination abilities. 2 is constructed by AgO bonds where DMSO function both as guest and bridging ligand. Further diffusion of NO into the solution of 1 and 2 generated two new compounds (1′ and 2′). All four compounds showed excellent broad-spectrum antimicrobial activities against gram-negative bacteria, gram-positive bacteria and yeast. The stronger antibacterial abilities of 1 against S. aureus and P. aeruginosa than those of 2 were evidenced by the smaller minimum inhibitory concentrations of silver ions (AgMICs) and the higher silver ion release rate in aqueous solution. It was concluded that the looser packing of 1 facilitate the silver ions releasing and play a more crucial role than binding mode and ligand-exchangeability. The enhanced P. aeruginosa inhibitions of 1′ and 2′ were elementarily ascribed to NO incorporation, supporting by their increased diameter of inhibition zones and decreased AgMICs.

Pharmacological evaluation and binding behavior of 4,4′-diamino-2,2′-stilbene disulfonic acid with metal ions using spectroscopic techniques

Industrial and human activities contribute significantly to the environmental contamination of heavy metal ions (HMIs), which have detrimental effects on aquatic life, plants, and animals, causing major toxicological problems. The commercially available 4,4′-diamino-2,2′-stilbenedisulfonic acid (DSD) has been playing a vital role in the detection of heavy metal ions and has significantly inhibited a variety of cancer cells in numerous field of modern science. The current investigation aimed to ensure the detection of heavy metals ions from the environment and fluorescence imaging of DSD in the treatment of cancer cells. Fluorescence and UV–Visible spectroscopic analysis was performed to sense the selective behavior of the probe DSD with several heavy metal ions, including Fe2+, K1+, Co2+, Ni2+, Zn2+, Cd2+, Pb2+, Mn2+, Sn2+, and Cr3+. Furthermore, DSD was subjected to examine enzyme inhibition such as anti-Alzheimer, anti-inflammatory, antioxidant, anticancer, and antimicrobial activities in search of multifaceted drugs. Test compounds have demonstrated dose-dependent responses in the in-vitro enzyme inhibition assays for acetylcholinesterase (AChE), butyrylcholinesterase (BChE), cyclooxygenase (COX), and lipoxygenase (LOX), as well as antioxidant [DPPH = 2,2-diphenyl-1-picrylhydrazyl and ABTS = 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid]. The DSD were shown to be more effective than the conventional medication galantamine in inhibiting acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), with an IC50 value of 12.18 and 20.87 μM, which is equivalent to the standard drug. The results obtained has revealed that DSD has the potential to become an effective sensor for the detection of Sn2+ ions over competing metal ions due to the inhibition of photo-induced electron transfer pathway (PET). The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide tetrazolium) test, demonstrated that DSD had strong anticancer effects against the brain cancer cell line NIH/3T3, HeLa and MCF-7 with an IC50 value of 32.59, 15.31 and 96.46 μM respectively. The antimicrobial testing has shown that DSD outperforms the standard drug cefixime against Candida albicans and Pseudomonas aeruginosa, respectively. This study makes a substantial contribution to the ongoing search for efficient treatments for breast cancer.

Voltage-dependent anion channel 1 mediates mitochondrial fission and glucose metabolic reprogramming in response to ionizing radiation

The ionizing radiation (IR) represents a formidable challenge as an environmental factor to mitochondria, leading to disrupt cellular energy metabolism and posing health risks. Although the deleterious impacts of IR on mitochondrial function are recognized, the specific molecular targets remain incompletely elucidated. In this study, HeLa cells subjected to γ-rays exhibited concomitant oxidative stress, mitochondrial structural alterations, and diminished ATP production capacity. The γ-rays induced a dose-dependent induction of mitochondrial fission, simultaneously manifested by an elevated S616/S637 phosphorylation ratio of the dynamin-related protein 1 (DRP1) and a reduction in the expression of the mitochondrial fusion protein mitofusin 2 (MFN2). Knockdown of DRP1 effectively mitigated γ-rays-induced mitochondrial network damage, implying that DRP1 phosphorylation may act as an effector of radiation-induced mitochondrial damage. The mitochondrial outer membrane protein voltage-dependent anion channel 1 (VDAC1) was identified as a crucial player in IR-induced mitochondrial damage. The VDAC1 inhibitor 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid (DIDS), counteracts the excessive mitochondrial fission induced by γ-rays, consequently rebalancing the glycolytic and oxidative phosphorylation equilibrium. This metabolic shift was uncovered to enhance glycolytic capacity, thus fortifying cellular resilience and elevating the radiosensitivity of cancer cells. These findings elucidate the intricate regulatory mechanisms governing mitochondrial morphology under radiation response. It is anticipated that the development of targeted drugs directed against VDAC1 may hold promise in augmenting the sensitivity of tumor cells to radiotherapy and chemotherapy.

1,3-(4,4'-dipyridinium disulfonic acid)propane dimethanesulfonate as an effective double-functional catalyst in preparing N,N′-Methylene bisamides, Tetrahydrochromeno-chromenes, and Pyrido-dipyrimidines

1,3-(4,4'-dipyridinium disulfonic acid)propane dimethanesulfonate as an effective double-functional catalyst in preparing N,N′-Methylene bisamides, Tetrahydrochromeno-chromenes, and Pyrido-dipyrimidines

UiO-66 membranes with confined naphthalene disulfonic acid for selective monovalent ion separation

The selective separation of monovalent ions remains a challenge because of the similar sub-nanometer sizes. Metal-organic frameworks (MOFs) are promising candidate membranes for ion selective separation based on the angstrom sized windows for size sieving. Here, to further enhance the monovalent ion selectivity, 1, 5-naphthalenedisulfonic acid tetrahydrate (NTDS) molecules with sulfonate groups are incorporated to offer a binding affinity, generating a UiO-66@NTDS membrane via the window-cavity structure confinement. In addition to the size sieving effect, the charge and affinity interaction can compensate the energy loss induced by the ion dehydration. Thus, the UiO-66@NTDS membranes exhibit elevated separation performance compared to the original UiO-66 membranes under the concentration gradient driven, accompanied by high monovalent cation permeation rates (i.e., 0.3–0.7 mol m−2 h−1) and mono-/divalent cation selectivities (i.e., ∼73 for K+/Mg2+, ∼57 for Na+/Mg2+, and ∼46 for Li+/Mg2+). This work provides guidelines for the development of efficient ion-selective MOF membranes via the combination of size sieving and interaction attraction.

Recycling of polyester bottle waste to generate functional acid dye in situ on wool

AbstractNowadays, waste management is gaining popularity to reduce the environmental impact made by human beings. There is a dire need to decrease the pollution caused by plastic materials. A gradual rise in the demand for polyester bottles has generated a need to recycle these materials. In the present work, an aromatic amine (4,4′‐(1,4‐phenylenebis(1,3,4‐oxadiazole‐5,2‐diyl)) dianiline) was prepared from the polyester bottle waste. The successful synthesis and chemical structure of the amine was confirmed by various characterization techniques such as Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy (1H NMR), and 13C NMR. The amine was diazotized and coupled with H‐acid (4‐amino‐5‐hydroxy‐2,7‐naphthalene disulfonic acid)‐treated wool fabric to generate acid dye in situ on the fabric. The coloration (L*, a*, b*, and K/S) and fastness properties of dyed wool were evaluated, and the samples were further analyzed for antibacterial and UV‐protective properties. The dyed wool was also characterized by FTIR to confirm the presence of the aromatic group of the dye. The introduction of dye structure on the wool increased the thermal stability of the fabric, which was confirmed through thermogravimetric analysis analysis. Antibacterial activity (>70%) and excellent UV protection were retained by dyed wool after 20 washes. Furthermore, the dyed wool was found nontoxic under the cytotoxicity evaluation test.

Lysine acetylation of Hsp16.3: Effect on its structure, chaperone function and influence towards the growth of Mycobacterium tuberculosis

Hsp16.3 plays a vital role in the slow growth of Mycobacterium tuberculosis via its chaperone function. Many secretory proteins, including Hsp16.3 undergo acetylation in vivo. Seven lysine (K) residues (K64, K78, K85, K114, K119, K132 and K136) in Hsp16.3 are acetylated inside pathogen. However, how lysine acetylation affects its structure, chaperone function and pathogen's growth is still elusive. We examined these aspects by executing in vitro chemical acetylation (acetic anhydride modification) and by utilizing a lysine acetylation mimic mutant (Hsp16.3-K64Q/K78Q/K85Q/K114Q/K119Q/K132Q/K136Q). Far- and near-UV CD measurements revealed that the chemically acetylated proteins(s) and acetylation mimic mutant has altered secondary and tertiary structure than unacetylated/wild-type protein. The chemical modification and acetylation mimic mutation also disrupted the oligomeric assembly, increased surface hydrophobicity and reduced stability of Hsp16.3, as revealed by GF-HPLC, 4,4′-dianilino-1,1′-binaphthyl-5,5′-disulfonic acid binding and urea denaturation experiments, respectively. These structural changes collectively led to an enhancement in chaperone function (aggregation and thermal inactivation prevention ability) of Hsp16.3. Moreover, when the H37Rv strain expressed the acetylation mimic mutant protein, its growth was slower in comparison to the strain expressing the wild-type/unacetylated Hsp16.3. Altogether, these findings indicated that lysine acetylation improves the chaperone function of Hsp16.3 which may influence pathogen's growth in host environment.

Structural insights into the orthosteric inhibition of P2X receptors by non-ATP analog antagonists.

P2X receptors are extracellular ATP-gated ion channels that form homo- or heterotrimers and consist of seven subtypes. They are expressed in various tissues, including neuronal and nonneuronal cells, and play critical roles in physiological processes such as neurotransmission, inflammation, pain, and cancer. As a result, P2X receptors have attracted considerable interest as drug targets, and various competitive inhibitors have been developed. However, although several P2X receptor structures from different subtypes have been reported, the limited structural information of P2X receptors in complex with competitive antagonists hampers the understanding of orthosteric inhibition, hindering the further design and optimization of those antagonists for drug discovery. We determined the cryogenic electron microscopy (cryo-EM) structures of the mammalian P2X7 receptor in complex with two classical competitive antagonists of pyridoxal-5'-phosphate derivatives, pyridoxal-5'-phosphate-6-(2'-naphthylazo-6'-nitro-4',8'-disulfonate) (PPNDS) and pyridoxal phosphate-6-azophenyl-2',5'-disulfonic acid (PPADS), and performed structure-based mutational analysis by patch-clamp recording as well as molecular dynamics (MD) simulations. Our structures revealed the orthosteric site for PPADS/PPNDS, and structural comparison with the previously reported apo- and ATP-bound structures showed how PPADS/PPNDS binding inhibits the conformational changes associated with channel activation. In addition, structure-based mutational analysis identified key residues involved in the PPNDS sensitivity of P2X1 and P2X3, which are known to have higher affinity for PPADS/PPNDS than other P2X subtypes.

Structural insights into the orthosteric inhibition of P2X receptors by non-ATP analog antagonists

P2X receptors are extracellular ATP-gated ion channels that form homo- or heterotrimers and consist of seven subtypes. They are expressed in various tissues, including neuronal and nonneuronal cells, and play critical roles in physiological processes such as neurotransmission, inflammation, pain, and cancer. As a result, P2X receptors have attracted considerable interest as drug targets, and various competitive inhibitors have been developed. However, although several P2X receptor structures from different subtypes have been reported, the limited structural information of P2X receptors in complex with competitive antagonists hampers the understanding of orthosteric inhibition, hindering the further design and optimization of those antagonists for drug discovery. We determined the cryogenic electron microscopy (cryo-EM) structures of the mammalian P2X7 receptor in complex with two classical competitive antagonists of pyridoxal-5'-phosphate derivatives, pyridoxal-5'-phosphate-6-(2'-naphthylazo-6'-nitro-4',8'-disulfonate) (PPNDS) and pyridoxal phosphate-6-azophenyl-2′,5′-disulfonic acid (PPADS), and performed structure-based mutational analysis by patch-clamp recording as well as molecular dynamics (MD) simulations. Our structures revealed the orthosteric site for PPADS/PPNDS, and structural comparison with the previously reported apo- and ATP-bound structures showed how PPADS/PPNDS binding inhibits the conformational changes associated with channel activation. In addition, structure-based mutational analysis identified key residues involved in the PPNDS sensitivity of P2X1 and P2X3, which are known to have higher affinity for PPADS/PPNDS than other P2X subtypes.

Insight into the synthesis and mechanism of oxacalix[4]arene based nanohybrids for dual readout sensing and removal of Hg2+ ions

Mercury contamination has been a major concern for decades and its removal from environment and natural waterbodies are of highest priority. Inspired by the fact to detect trace amount of mercury and consequently removal of the same, here we present a silver nanoparticle based affordable, rapid and sensitive probe for inspecting the mercury levels on various waterbodies and soil samples with exceptional sensitivity (12 nM). This study reports the design, synthesis and characterization of novel disulfonic acid functionalized oxacalix[4]arene appended silver nanoparticles (DSOC@AgNPs). Driven by the distinct color change phenomena of DSOC@AgNPs upon interaction with Hg2+ ions, we have fabricated a paper strip-based ready-to-use detection kit for rapid detection of mercury ions up to sub-nanomolar concentration. Moreover, DSOC@AgNPs modified screen-printed carbon electrodes (SPCE) have been developed and utilized as a rapid detection kit for mercury in environmental samples. DSOC@AgNPs encapsulated ZIF-8 nanohybrid (DSOC@AgNPs-ZIF) have been employed for the removal of Hg2+ ions from mercury contaminated wastewater with a removal efficiency of 95%. Incidentally, this is the first report for the removal of Hg2+ ions (CH3Hg+ and Hg2+ species) using oxacalixarene-stabilized AgNPs. Further, the surface-modified Rh6G-DSOC@AgNPs reveal its bio-imaging potentiality for mercury detection in living systems and also exhibited dose-dependent cytotoxicity against MCF-7 cells, with an IC50 value of 354.62 μM.

Design and Synthesis of Comb‐Like Bisulfonic Acid Proton Exchange Membrane with Regulated Microstructure

AbstractThe design and synthesis of proton exchange membranes (PEMs) with controllable microstructure and sulfonation degree play a crucial role in enhancing their performance and expanding their application. In this study, the disulfonic acid monomer is designed and prepared to synthesize the comb‐like disulfonic PEMs with controllable ion exchange capacity. The results show that the side chain structure and more concentrated sulfonic acid groups facilitate the aggregation of sulfonic acid groups in the polymer, improve the microphase separation morphology of PEMs, and increase the ionic conductivity. The proton conductivity of the DS‐PXIDI‐60 membrane is approximately 300 mS cm−1. The PEMs with controllable microstructure are prepared by introducing comonomers, including 9,9‐dimethylxanthrene, biphenyl, and p‐terphenyl, with different reactivity, spatial structure, and solubility. Biphenyl is copolymerized to form a copolymer with an alternating structure, and 9, 9‐dimethylxanthrene is copolymerized to form a random copolymer. In addition, it is worth noting that p‐terphenyl is copolymerized to form a microblock structure of the copolymer, with more excellent comprehensive properties. DS‐PXITp‐60 exhibits better performance than Nafion 212 in redox­flow batteries and fuel cells. Therefore, such molecular design and synthesis strategies provide a reference guide for the development of high‐performance PEMs.

Construction of triptycene molecular rotors with intermeshing arrangement and low rotational barrier

Abstract Molecular rotors are one of the building blocks of molecular machines and they are nano-sized with mechanically rotating moieties. Among them, intermeshing triptycenes with a gear-like skeleton allow the construction of a molecular rotor that transmits rotational motion. For triptycenes to mesh with each other without loss of rotation, intermeshing them in parallel and adjusting the distance between their axes to 8.1 Å are required. However, with conventional methods, because of the restrictions on bond lengths and atomic radii, achieving an ideal arrangement in which the triptycenes mesh in parallel at 8.1 Å has been difficult. In this work, we synthesized disulfonic acid containing a triptycene as a rotator and combined it with amines of 2 different steric factors (normal-amylamine [nAmA] and guanidine [Gu]), which allowed us to prepare organic salts with varying arrangements of triptycenes. In the organic salt with the planar amine (Gu), the crystal structure was close to the ideal intermeshing arrangement of the triptycene and the distance between their axes was 7.7 Å. The T1ρ 13C spin-lattice relaxation time using solid-state nuclear magnetic resonance (NMR) demonstrated that triptycene rotates efficiently at 24 kHz at 313 K with a low rotational barrier (10.9 kcal/mol) compared with non-intermeshing structures.

Aggregation and Capacity Limiting Effects in Anthraquinone-Based Flow Battery Negolytes

Anthraquinone-based molecules are promising electroactive materials for use in aqueous organic flow batteries. At high concentrations in aqueous solutions, the well-known negolyte molecule anthraquinone disulfonic acid (AQDS) molecule has been observed to aggregate under near-neutral and acidic conditions. Aggregation has been hypothesized to be directly linked to observed concurrent capacity reduction. In this study, we investigated three different water-soluble anthraquinones in electrolytes of varying compositions and pH to gain further insight into the possible causes of capacity loss. We used low-field benchtop 1H-NMR and diffusion NMR measurements directly in non-deuterated aqueous flow-battery electrolytes to investigate molecular aggregation. Single-cell testing was performed under exhaustive electrolysis conditions to determine the number of electrons exchanged per molecule. We observed a decrease in the number of electrons exchanged per molecule in the presence of carbonate ions due to CO2 adduct formation. The aggregation constants were determined from both concentration-dependent chemical shifts and self-diffusion coefficients. We show that aggregation of the oxidized form of all three molecules studied here occurs under near-neutral and alkaline conditions and does not affect the number of accessible e−.

1,3-(4,4′-bipyridinium disulfonic acid) propane-dihydrogen sulfate as highly effectual bi-functional catalysts for the rapid preparing chromeno[4,3-b]chromenes and pyrido[2,3-d:6,5-d′]dipyrimidines

1,3-(4,4′-bipyridinium disulfonic acid) propane-dihydrogen sulfate as highly effectual bi-functional catalysts for the rapid preparing chromeno[4,3-b]chromenes and pyrido[2,3-d:6,5-d′]dipyrimidines

Determination of N-Acetyl-L-cysteine Ethyl Ester (NACET) by Sequential Injection Analysis.

New sequential injection analysis (SIA) methods with optical sensing for the determination of N-acetyl-L-cysteine ethyl ester (NACET) have been developed and optimized. NACET is a potential drug and antioxidant with advantageous pharmacokinetics. The methods involve the reduction of Cu(II) in its complexes with neocuproine (NCN), bicinchoninic acid (BCA), and bathocuproine disulfonic acid (BCS) to the corresponding chromophoric Cu(I) complexes by the analyte. The absorbance of the Cu(I) complexes with NCN, BCA, and BCS was measured at their maximum absorbance wavelengths of 458, 562, and 483 nm, respectively. The sensing manifold parameters and experimental conditions were optimized for each of the Cu(II) complexes used. Under optimal conditions, the corresponding linear calibration ranges, limits of detection, and sampling rates were 8.0 × 10-6-2.0 × 10-4 mol L-1, 5.5 × 10-6 mol L-1, and 60 h-1 for NCN; 6.0 × 10-6-1.0 × 10-4 mol L-1, 5.2 × 10-6 mol L-1, and 60 h-1 for BCA; and 4.0 × 10-6-1.0 × 10-4 mol L-1, 2.6 × 10-6 mol L-1, and 78 h-1 for BCS. The Cu(II)-BCS complex was found to be best performing in terms of sensitivity and sampling rate. Usual excipients in pharmaceutical preparations did not interfere with NACET analysis.

The role of solvation on the conformational landscape of α-synuclein.

Native ion mobility mass spectrometry has been used extensively to characterize ensembles of intrinsically disordered protein (IDP) conformers, but the extent to which the gaseous measurements provide realistic pictures of the solution conformations for such flexible proteins remains unclear. Therefore, we systematically studied the relationship between the solution and gaseous structural ensembles by measuring electrospray charge state and collision cross section (CCS) distributions for cationic and anionic forms of α-synuclein (αSN), an anionic protein in solution, as well as directly probed gas phase residue to residue distances via ion/ion reactions between gaseous α-synuclein cations and disulfonic acid linkers that form strong electrostatic bonds. We also combined results from in-solution protein crosslinking identified from native tandem mass spectrometry (MS/MS) with an initial αSN ensemble generated computationally by IDPConformerGenerator to generate an experimentally restrained solution ensemble of αSN. CCS distributions were directly calculated for the solution ensembles determined by NMR and compared to predicted gaseous conformers. While charge state and collision cross section distributions are useful for qualitatively describing the relative structural dynamics of proteins and major conformational changes induced by changes to solution states, the predicted and measured gas phase conformers include subpopulations that are significantly different than those expected from completely "freezing" solution conformations and preserving them in the gas phase. However, insights were gained on the various roles of solvent in stabilizing various conformers for extremely dynamic proteins like α-synuclein.

CORROSION RESISTANCE OF ZINC GALVANIC DEPOSITS OBTAINED BY THE ELECTROCHEMICAL 3D PRINTING METHOD

The article is devoted to the implementation of the process of electrochemical 3D printing of zinc products and the determination of the effect of the methodof their production on corrosion resistance. The possibility of electrochemical 3D printing of zinc objects with a fine-crystalline compact structure using high-speed sulfate plating electrolyte has been shown. The most resilient and elastic zinc depositswere obtained in the electrolyte without the addition of organic additives and when gelatin was added to the electrolyte. The use of naphthalene disulfonic acid of 1,5-disodium salt made it possible to obtain the most finely crystalline and semi-glossy zinc deposits, but the fragility of the deposits increased somewhat. Conducted studies of the corrosion resistance of printed zinc objects showed that the use of electrochemical 3D printing as a method of obtaining and introducing organic additives into the electrolyte does not lead to a decrease in the corrosion resistance of the metal