Enhancing the Thermostability and solubility of a single-domain catalytic antibody.

Catalytic antibodies have the ability to bind to and degrade antigens, offering a significant potential for therapeutic use. The light chain of an antibody, UA15-L, can cleave the peptide bond of Helicobacter pylori urease, thus inhibiting the spread of the bacteria. However, the variable domain of UA15-L has a poor thermostability and solubility.

ChIP-Seq Analysis of AtfA Interactions in Reveals Its Involvement in Aflatoxin Metabolism and Virulence Under Oxidative Stress.

The risk of contamination is expanding with global warming. Targeting the pathogenicity of at its source and diminishing its colonization within the host may be a potential control strategy. Oxidative stress transcription factor AtfA plays a pivotal role in pathogenicity by combating reactive oxygen species (ROS) generated by host immune cells.

Positive activation entropy of Bacillus circulans xylanase catalyzed ONPX hydrolysis: A mechanistic and engineering study.

Transition state (TS) stabilization by enzymes greatly accelerates catalytic reactions. For some enzymes, the TS complex has entropy higher than enzyme substrate (ES) complex. But the origin of favorable entropy remains unclear.

Quantification of CH and NH/π-Stacking Interactions in Cells Using Nuclear Magnetic Resonance Spectroscopy.

π-Stacking, a type of noncovalent interactions involving aromatic residues, plays an important role in protein folding and function. In this work, an attempt has been made to measure CH/π and NH/π stacking interactions in a protein in cells using a combined double-mutant cycle and nuclear magnetic resonance spectroscopy method. The results show that the CH/π and NH/π stacking interactions are generally weaker in cells than those in the buffer.

Protein Allostery Study in Cells Using NMR Spectroscopy.

Protein allostery is commonly observed in vitro. But how protein allostery behaves in cells is unknown. In this work, a protein monomer-dimer equilibrium system was built with the allosteric effect on the binding characterized using NMR spectroscopy through mutations away from the dimer interface.

Ferrous sulphate triggers ferroptosis in Candida albicans and cures vulvovaginal candidiasis in a mouse model.

Candida albicans is the most leading cause of life-threatening fungal invasive infections, especially for vulvovaginal candidiasis (VVC). Resistance and tolerance to common fungicide has risen great demands on alternative strategies for treating C. albicans infections.

Fabrication and 3D printing of Pickering emulsion gel based on by-products protein.

Pickering emulsion gel (PEG) stabilized by the protein extracted from the by-product of , combining with xanthan gum (XG), was formulated as 3D printing ink. Hydrogen bonds are formed in XG/protein hybrid particles. Afterwards, PEG was developed.

Structural insight into why S-linked glycosylation cannot adequately mimic the role of natural O-glycosylation.

There is an increasing interest in using S-glycosylation as a replacement for the more commonly occurring O-glycosylation, aiming to enhance the resistance of glycans against chemical hydrolysis and enzymatic degradation. However, previous studies have demonstrated that these two types of glycosylation exert distinct effects on protein properties and functions. In order to elucidate the structural basis behind the observed differences, we conducted a systematic and comparative analysis of 6 differently glycosylated forms of a model glycoprotein, CBM, using NMR spectroscopy and molecular dynamic simulations.

Intracellular environment can change protein conformational dynamics in cells through weak interactions.

Conformational dynamics is important for protein functions, many of which are performed in cells. How the intracellular environment may affect protein conformational dynamics is largely unknown. Here, loop conformational dynamics is studied for a model protein in cells by using nuclear magnetic resonance (NMR) spectroscopy.

Improving the Enzymatic Activity and Stability of a Lytic Polysaccharide Monooxygenase.

Lytic Polysaccharide Monooxygenases (LPMOs) are copper-dependent enzymes that play a pivotal role in the enzymatic conversion of the most recalcitrant polysaccharides, such as cellulose and chitin. Hence, protein engineering is highly required to enhance their catalytic efficiencies. To this effect, we optimized the protein sequence encoding for an LPMO from (LPMO10A) using the sequence consensus method.

Preparation and application of tremella polysaccharide based chrome free tanning agent for sheepskin processing.

The abuse of chrome tanning agent in leather processing has caused great harm to human health and the natural environment. We use tremella polysaccharides (TP), lentinan (LNT) and konjac gum (KG) as raw materials, and sodium periodate as oxidant to prepare the corresponding polysaccharide tanning agent. Tremella polysaccharide was selected as the best tanning agent according to the shrinkage temperature, and the subsequent experiments were carried out.

Engineering the Active Site Lid Dynamics to Improve the Catalytic Efficiency of Yeast Cytosine Deaminase.

Conformational dynamics is important for enzyme catalysis. However, engineering dynamics to achieve a higher catalytic efficiency is still challenging. In this work, we develop a new strategy to improve the activity of yeast cytosine deaminase (yCD) by engineering its conformational dynamics.

Blended cumin/Zanthoxylum essential oil improve the antibacterial, fresh-keeping performance and flavor of chilled fresh mutton.

Microbial pollution and fat oxidation are the main factors that induce the deterioration in the quality of chilled fresh mutton. This study evaluated the effects of cumin (Cuminum cyminum) essential oil (CEO), Zanthoxylum essential oil (ZEO), and blended cumin/zanthoxylum essential oil (BEO) on the antibacterial, preservation of freshness, and flavor improvement of chilled fresh mutton. The results show that BEO exerts a good inhibition effect on microbial growth, lipid oxidation, and the formation of TVB-N, as well as slowing down the rate of juice loss under chilled conditions.

Ferric chloride induces ferroptosis in Pseudomonas aeruginosa and heals wound infection in a mouse model.

Background: Pseudomonas aeruginosa is one of the most common pathogens that lead to fatal human infection. This Gram-negative pathogen has evolved complex drug resistance, which poses significant challenges to the current antibiotic-dependent healthcare system. New therapeutic approaches are urgently required to treat infections caused by P.

An "intelligent -responsive" bactericidal system based on OSA-starch Pickering emulsion.

Pickering emulsion based on OSA-starch was developed in this study as an intelligent delivery system for the application of thymol against foodborne pathogens. Morphology and microstructure characterization showed that the Pickering emulsion was an O/W type emulsion and stayed stable at starch concentration of 200 mg/mL and oil fraction at 30 % with particle size of 10 μm and absolute Zeta potential of -12.5 mV.

Detecting the Hydrogen Bond Cooperativity in a Protein β-Sheet by H/D Exchange.

The hydrogen bond (H-bond) cooperativity in the β-sheet of GB3 is investigated by a NMR hydrogen/deuterium (H/D) exchange method. It is shown that the weakening of one backbone N-H…O=C H-bond between two β-strands, β1 and β2, due to the exchange of NH to ND of the H-bond donor in β1, perturbs the chemical shift of C, C, H, H, and N of the H-bond acceptor and its following residue in β2. Quantum mechanical calculations suggest that the -H-bond chemical shift isotope effect is caused by the structural reorganization in response to the H-bond weakening.

Fe protects postharvest pitaya ( from infection by directly binding its genomic DNA.

is a postharvest fungus, causing pitaya fruit decay and limiting pitaya value and shelf life. However, safer and more efficient methods for preventing contamination for pitaya fruit remain to be investigated. In this study, we successfully proved exogenous Fe could inhibit colonization in pitaya fruit and extend pitaya's shelf life after harvest.

Water-Locked Eutectic Electrolyte Enables Long-Cycling Aqueous Sodium-Ion Batteries.

Aqueous sodium batteries are one of the awaited technologies for large-scale energy storage, but remain poorly rechargeable because of the reactivity issues of water. Here, we present a hydrated eutectic electrolyte featuring a water-locked effect, which is exceptional in that the O-H bond of water is essentially strengthened via weak hydrogen bonding (relative to the original HO-HO hydrogen bonds) to low-donor-number anions and ligands. Even without interphase protection, both the anodic and cathodic water electrodecomposition reactions are delayed, extending the aqueous potential window to 3.

A Tyrosine Phosphoproteome Analysis Approach Enabled by Selective Dephosphorylation with Protein Tyrosine Phosphatase.

Protein tyrosine phosphorylation (pTyr) plays a prominent role in signal transduction and regulation in all eukaryotic cells. In conventional immunoaffinity purification (IP) methods, phosphotyrosine peptides are isolated from the digest of cellular protein extracts with a phosphotyrosine-specific antibody and are identified by tandem mass spectrometry. However, low sensitivity, poor reproducibility, and high cost are universal concerns for IP approaches.

Quantifying Protein Electrostatic Interactions in Cells by Nuclear Magnetic Resonance Spectroscopy.

Most proteins perform their functions in cells. How the cellular environment modulates protein interactions is an important question. In this work, electrostatic interactions between protein charges were studied using in-cell nuclear magnetic resonance (NMR) spectroscopy.

Exogenous Iron Induces NADPH Oxidases-Dependent Ferroptosis in the Conidia of .

is saprophytic soil fungus that contaminates seed crops with the carcinogenic secondary metabolite aflatoxin, posing a significant threat to humans and animals. Ferrous sulfate is a common iron supplement that is used to the treatment of iron-deficiency anemia. Here, we identified an unexpected inhibitory role of ferrous sulfate on .

EGCG Alleviates Oxidative Stress and Inhibits Aflatoxin B Biosynthesis via MAPK Signaling Pathway.

Aflatoxin biosynthesis has established a connection with oxidative stress, suggesting a prevention strategy for aflatoxin contamination via reactive oxygen species (ROS) removal. Epigallocatechin gallate (EGCG) is one of the most active and the richest molecules in green tea with well-known antioxidant effects. Here, we found EGCG could inhibit aflatoxin B (AFB) biosynthesis without affecting mycelial growth in , and the arrest occurred before the synthesis of toxin intermediate metabolites.

Enabling highly ()-enantioselective epoxidation of styrene by engineering unique non-natural P450 peroxygenases.

Unlike the excellent ()-enantioselective epoxidation of styrene performed by natural styrene monooxygenases (ee > 99%), the ()-enantioselective epoxidation of styrene has not yet achieved a comparable efficiency using natural or engineered oxidative enzymes. This report describes the HO-dependent ()-enantioselective epoxidation of unfunctionalized styrene and its derivatives by site-mutated variants of a unique non-natural P450BM3 peroxygenase, working in tandem with a dual-functional small molecule (DFSM). The observed ()-enantiomeric excess (ee) of styrene epoxidation is up to 99% with a turnover number (TON) of 918 by the best enantioselective mutant F87A/T268I/L181Q, while the best active mutant F87A/T268I/V78A/A184L (with 98% ee) gave a catalytic TON of 4350, representing the best activity of a P450 peroxygenase towards styrene epoxidation to date.