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The Science of the Total Environment Aug 2023Biochar, a potential alternative of infield crop residue burning, can prevent nutrient leaching from soil and augment soil fertility. However, pristine biochar contains...
Biochar, a potential alternative of infield crop residue burning, can prevent nutrient leaching from soil and augment soil fertility. However, pristine biochar contains low cation (CEC) and anion (AEC) exchange capacity. This study developed fourteen engineered biochar by treating a rice straw biochar (RBC-W) first separately with different CEC and AEC enhancing chemicals, and then with their combined treatments to increase CEC and AEC in the novel biochar composites. Following a screening experiment, promising engineered biochar, namely RBC-W treated with O-HCl-FeCl (RBC-O-Cl), HSO-HNO-HCl-FeCl (RBC-A-Cl), and NaOH-Fe(NO)(RBC-OH-Fe), underwent physicochemical characterization and soil leaching-cum nutrient retention studies. RBC-O-Cl, RBC-A-Cl, and RBC-OH-Fe recorded a spectacular rise in CEC and AEC over RBC-W. All the engineered biochar remarkably reduced the leaching of NH-N, NO -N, PO-P and K from a sandy loam soil and increased retention of these nutrients. RBC-O-Cl at 4.46 g kg dosage emerged as the most effective soil amendment increasing the retention of above ions by 33.7, 27.8, 15.0, and 5.74 % over a comparable dose of RBC-W. The engineered biochar could thus enhance plants' nutrient use efficiency and reduce the use of costly chemical fertilizers that are harmful to environmental quality.
Topics: Oryza; Charcoal; Soil; Anions; Nutrients; Cations
PubMed: 37100159
DOI: 10.1016/j.scitotenv.2023.163681 -
Journal of Hazardous Materials Jul 2023By linking the cation and anion motifs of ionic liquids (ILs), zwitterionic liquids (ZILs) exhibit at least 146-2740 and 112-1550 folds less cytotoxicity in human...
By linking the cation and anion motifs of ionic liquids (ILs), zwitterionic liquids (ZILs) exhibit at least 146-2740 and 112-1550 folds less cytotoxicity in human gastric and colon cells than those of the structurally related ILs. Computer simulation shows that ZIL molecules hardly penetrate the cell membranes in contrast to ILs. These findings reveal a novel mechanism for ZILs to evade cytotoxicity, establishing a structure-based design principle for the next generation of sustainable ZILs.
Topics: Humans; Ionic Liquids; Computer Simulation; Anions
PubMed: 37080032
DOI: 10.1016/j.jhazmat.2023.131430 -
Water Research Oct 2023The presence of organic micropollutants (OMPs) in water has been threatening human health and aquatic ecosystems worldwide. Ultraviolet-based advanced treatment... (Review)
Review
The presence of organic micropollutants (OMPs) in water has been threatening human health and aquatic ecosystems worldwide. Ultraviolet-based advanced treatment processes (UV-ATPs) are one of the most effective and promising technologies to transform OMPs in water; therefore, an increasing number of emerging UV-ATPs are proposed. However, appropriate selection of UV-ATPs for practical applications is challenging because each UV-ATP generates different types and concentrations of reactive species (RSs) that may not be sufficient to degrade specific types of OMPs. Furthermore, the concentrations and types of RSs are highly influenced by anions and dissolved organic matter (DOM) coexisting in real waters, making systematic understandings of their interfering mechanisms difficult. To identify and address the knowledge gaps, this review provides a comparison of the generations and variations of various types of RSs in different UV-ATPs. These analyses not only prove the importance of water matrices on formation and consumption of primary and secondary RSs under different conditions, but also highlight the non-negligible roles of optical properties and reactivities of DOM and anions. For example, different UV-ATPs may be applicable to different target OMPs under different conditions; and the concentrations and roles of secondary RSs may outperform those of primary RSs in OMP degradation for real applications. With continuous progress and outstanding achievements in the UV-ATPs, it is hoped that the findings and conclusions of this review could facilitate further research and application of UV-ATPs.
Topics: Humans; Ecosystem; Dissolved Organic Matter; Technology; Water
PubMed: 37683496
DOI: 10.1016/j.watres.2023.120537 -
ACS Chemical Biology Aug 2023Hydrophobic microdomains, also known as hydrophobic patches, are essential for many important biological functions of water-soluble proteins. These include ligand or...
Hydrophobic microdomains, also known as hydrophobic patches, are essential for many important biological functions of water-soluble proteins. These include ligand or substrate binding, protein-protein interactions, proper folding after translation, and aggregation during denaturation. Unlike transmembrane domains, which are easily recognized from stretches of contiguous hydrophobic sidechains in amino acids via primary protein sequence, these three-dimensional hydrophobic patches cannot be easily predicted. The lack of experimental strategies for directly determining their locations hinders further understanding of their structure and function. Here, we posit that the small triatomic anion N (azide) is attracted to these patches and, in the presence of an oxidant, forms a radical that covalently modifies C-H bonds of nearby amino acids. Using two model proteins (BSA and lysozyme) and a cell-free lysate from the model higher plant , we find that radical-mediated covalent azidylation occurs within buried catalytic active sites and ligand binding sites and exhibits similar behavior to established hydrophobic probes. The results herein suggest a model in which the azido radical is acting as an "affinity reagent" for nonaqueous three-dimensional protein microenvironments and is consistent with both the nonlocalized electron density of the azide moiety and the known high reactivity of azido radicals widely used in organic chemistry syntheses. We propose that the azido radical is a facile means of identifying hydrophobic microenvironments in soluble proteins and, in addition, provides a simple new method for attaching chemical handles to proteins without the need for genetic manipulation or specialized reagents.
Topics: Water; Ligands; Azides; Proteins; Amino Acids
PubMed: 37463134
DOI: 10.1021/acschembio.3c00224 -
Protein Science : a Publication of the... Oct 2023Weak molecular interactions play an important role in protein structure and function. Computational tools that identify weak molecular interactions are, therefore,...
Weak molecular interactions play an important role in protein structure and function. Computational tools that identify weak molecular interactions are, therefore, valuable for the study of proteins. Here, we present AQcalc, a web server (https://aqcalcbiocomputing.com/) that can be used to identify anion-quadrupole (AQ) interactions, which are weak interactions involving aromatic residue (Trp, Tyr, and Phe) ring edges and anions (Asp, Glu, and phosphate ion) both within proteins and at their interfaces (protein-protein, protein-nucleic acids, and protein-lipid bilayer). AQcalc identifies AQ interactions as well as clusters involving AQ, cation-π, and salt bridges, among others. Utilizing AQcalc we analyzed weak interactions in protein models, even in the absence of experimental structures, to understand the contributions of weak interactions to deleterious structural changes, including those associated with oncogenic and germline disease variants. We identified several deleterious variants with disrupted AQ interactions (comparable in frequency to cation-π disruptions). Amyloid fibrils utilize AQ to bury anions at frequencies that far exceed those observed for globular proteins. AQ interactions were detected three and five times more frequently than the hydrogen-bonded AQ (HBAQ) in fibril structures and protein-lipid bilayer interfaces, respectively. By contrast, AQ and HBAQ interactions were detected with similar frequencies in globular proteins. Collectively, these findings suggest AQcalc will be effective in facilitating fine structural analysis. As other web utilities designed to identify protein residue interaction networks do not report AQ interactions, wide use of AQcalc will enrich our understanding of residue interaction networks and facilitate hypothesis testing by identifying and experimentally characterizing these comparably weak but important interactions.
Topics: Lipid Bilayers; Models, Molecular; Proteins; Anions; Cations
PubMed: 37596782
DOI: 10.1002/pro.4762 -
Protein Expression and Purification Oct 2023In downstream processing of protein therapeutics, ion exchange (IEX) chromatography is a powerful tool for removing byproducts whose isoelectric point (pI) is...
In downstream processing of protein therapeutics, ion exchange (IEX) chromatography is a powerful tool for removing byproducts whose isoelectric point (pI) is appreciably different from that of the product. Although in theory for a given case cation exchange (CEX) and anion exchange (AEX) chromatography should be equally effective for separation, in reality they may show different effectiveness. In the current work, with a case study, we demonstrated that AEX is more effective than CEX chromatography at removing the associated byproducts. In addition, we screened AEX resins and loading conditions to achieve best separation. Finally, we demonstrated that effective separation was achieved with the selected resin/condition, and chromatography performance was comparable between runs conducted at low and high load densities, suggesting that the developed process was relatively robust. The procedure described in this work can be used as a general approach for selecting resin and loading condition that allow for effective and robust removal of byproduct that binds weaker than the product to the selected type of column.
Topics: Chromatography, Ion Exchange; Anion Exchange Resins; Anions; Cations
PubMed: 37209930
DOI: 10.1016/j.pep.2023.106297 -
Journal of Chromatography. A Aug 2023The influence of the resin structure, on the competitive binding and separation of a two-component protein mixture with anion exchange resins is evaluated using...
The influence of the resin structure, on the competitive binding and separation of a two-component protein mixture with anion exchange resins is evaluated using conalbumin and green fluorescent protein as a model system. Two macroporous resins, one with large open pores and one with smaller pores, are compared to a resin with grafted polymers. Investigations include measurements of single and two-component isotherms, batch uptake kinetics and two-component column breakthrough. On both macroporous resins, the weaker binding protein, conalbumin, is displaced by the stronger binding green fluorescent protein. For the large pore resin, this results in a pronounced overshoot and efficient separation by frontal chromatography. The polymer-grafted resin exhibits superior capacity and kinetics for one-component adsorption, but is unable to achieve separation due to strongly hindered counter-diffusion. Intermediate separation efficiency is obtained with the smaller pore resin. Confocal laser scanning microscopy provides a mechanistic explanation of the underlying intra-particle diffusional phenomena revealing whether unhindered counter-diffusion of the displaced protein can occur or not. This study demonstrates that the resin's intra-particle structure and its effects on diffusional transport are crucial for an efficient separation process. The novelty of this work lies in its comprehensive nature which includes examples of the three most commonly used resin structures: a small pore agarose matrix, a large-pore polymeric matrix, and a polymer grafted resin. Comparison of the protein adsorption properties of these materials provides valuable clues about advantages and disadvantages of each for anion exchange chromatography applications.
Topics: Adsorption; Green Fluorescent Proteins; Conalbumin; Anion Exchange Resins; Polymers; Chromatography, Ion Exchange; Kinetics; Anions
PubMed: 37453173
DOI: 10.1016/j.chroma.2023.464208 -
Journal of Biological Inorganic... Oct 2023Superoxide dismutases (SODs) are enzymes that catalyze the dismutation of the superoxide radical anion into O and HO in a two-step reaction. They are ubiquitous to all...
Superoxide dismutases (SODs) are enzymes that catalyze the dismutation of the superoxide radical anion into O and HO in a two-step reaction. They are ubiquitous to all forms of life and four different types of metal centers are detected, dividing this class of enzymes into Cu-/Zn-, Ni-, Mn-, and Fe-SODs. In this study, a superoxide dismutase from the thermophilic bacteria Thermobifida fusca (TfSOD) was cloned and expressed before the recombinant enzyme was characterized. The enzyme was found to be active for superoxide dismutation measured by inhibition of cytochrome c oxidation and the inhibition of the autoxidation of pyrogallol. Its pH-optimum was determined to be 7.5, while it has a broad temperature optimum ranging from 20 to 90 °C. Combined with the T that was found to be 78.5 ± 0.5 °C at pH 8.0, TfSOD can be defined as a thermostable enzyme. Moreover, the crystal structure of TfSOD was determined and refined to 1.25 Å resolution. With electron paramagnetic resonance spectroscopy, it was confirmed that iron is the metal co-factor of TfSOD. The cell potential (E) for the TfSOD-Fe/TfSOD-Fe redox couple was determined to be 287 mV.
Topics: Superoxide Dismutase; Superoxides; Hydrogen Peroxide; Thermobifida
PubMed: 37725277
DOI: 10.1007/s00775-023-02019-9 -
Environmental Research Aug 2023In this study, the feasibility of Mg/Al layered double hydroxides (LDH) functionalized coffee ground waste biochars (LDH@CWGB) as a potential adsorbent to selectively...
Enhanced selectivity and recovery of phosphate and nitrate ions onto coffee ground waste biochars via co-precipitation of Mg/Al layered double hydroxides: A potential slow-release fertilizer.
In this study, the feasibility of Mg/Al layered double hydroxides (LDH) functionalized coffee ground waste biochars (LDH@CWGB) as a potential adsorbent to selectively recover phosphate (PO) and nitrate (NO) ions in aqueous phases and their consecutive uses as a slow-release fertilizer for stimulating the plant growth were identified. The higher adsorption capacity of PO and NO ions by LDH@CWGB (PO = 6.98 mgP/g, NO = 2.82 mgN/g) compared with pristine coffee ground waste biochars (CWGB; PO = 0.19 mgP/g, NO = 0.32 mgN/g) was mainly due to the incorporation of Mg/Al mixed oxides and Cl contents. Chemisorption and intra-particle mainly controlled the adsorptive recovery of PO and NO ions by CWGB and LDH@CWGB in aqueous phases and their adsorption toward CWGB and LDH@CWGB proceeded endothermically and spontaneously. The changes in the major adsorption mechanisms of PO and NO ions from ligand exchange (CWGB) to electrostatic surface complexation and anion-exchange (LDH@CWGB) supported the conclusion that the alternation of the surface features through Mg/Al LDH functionalization might improve selectivity and adsorption capacity of PO and NO ions onto CWGB under the co-existence of Cl, SO, and HCO ions. Since PO- and NO-loaded LDH@CWGB exhibited much higher seed germination, root and shoot growth rates of garden cress seeds (Lepidium sativum L) than other liquid and solid matrices, including 5 mgP/L PO and 5 mgN/L NO, 10 mgP/L PO and 10 mgN/L NO, and LDH@CWGB, it can be postulated that PO- and NO-loaded LDH@CWGB could be practically applicable to the agricultural field as a slow-release fertilizer to facilitate the seed germination, root and shoot growth of the plants.
Topics: Phosphates; Nitrates; Fertilizers; Coffee; Hydroxides; Water; Adsorption; Kinetics
PubMed: 37257744
DOI: 10.1016/j.envres.2023.116266 -
ACS Sensors Nov 2023Fluoride ions are highly relevant in environmental and biological sciences, and there is a very limited number of established fluoride chemical sensors. Previous...
Fluoride ions are highly relevant in environmental and biological sciences, and there is a very limited number of established fluoride chemical sensors. Previous fluoride-selective optodes were demonstrated with metal-porphyrin as the ionophore and required a chromoionophore for optical signal transduction. We demonstrate here novel optical fluoride sensing with nano-optodes containing an aluminum-phthalocyanine complex (AlClPc) as the single active sensing component, simplifying the conventional ion-selective optodes approach. The fluoride nano-optodes were interrogated in the absorbance and fluorescence modes in the near-infrared region, with absorption around 725 nm and emission peaks at 720 and 800 nm, respectively. The nano-optodes exhibited a lower detection limit around 0.1 μM and good selectivity over a range of common anions including ClO, Cl, Br, I, SO, NO, and AcO. Furthermore, the nano-optodes were physically entrapped in agarose hydrogels to allow distance-based point-of-care testing (POCT) applications. The 3D networks of the agarose hydrogel were able to filter off large particulates in the samples without stopping fluoride ions to reach the nano-optodes. The fluoride concentrations in real samples including river water, mineral water, and groundwater were successfully determined with the distance-based sensing hydrogel, and the results agreed well with those from commercial fluoride electrodes. Therefore, the results in this work lay the groundwork for the optical detection of fluoride in environmental samples without very sophisticated sample manipulation.
Topics: Fluorides; Aluminum; Hydrogels; Sepharose
PubMed: 37963263
DOI: 10.1021/acssensors.3c01848