Screening and isolation of quorum sensing inhibitors of Pseudomonas aeruginosa from Phellodendron amurense extracts using bio-affinity chromatography.

Drug-resistant bacterial infections pose a significant challenge in the field of bacterial disease treatment. Finding new antibacterial pathways and targets to combat drug-resistant bacteria is crucial. The bacterial quorum sensing (QS) system regulates the expression of bacterial virulence factors.

Precision engineering of antibodies: A review of modification and design in the Fab region.

The binding of functional groups to antibodies is crucial for disease treatment, diagnosis, and basic scientific research. Traditionally, antibody modifications have focused on the Fc region to maintain antigen-antibody binding activity. However, such modifications may impact critical antibody functions, including immune cell surface receptor activation, cytokine release, and other immune responses.

Screening of inhibitors on successful covalent tyrosinase coupling with help from SpyBank.

Microbial metabolites are an important source of tyrosinase (TYR) inhibitors because of their rich chemical diversity. However, because of the complex metabolic environment of microbial products, it is difficult to rapidly locate and identify natural TYR inhibitors. Affinity-based ligand screening is an important method for capturing active ingredients in complex samples, but ligand immobilization is an important factor affecting the screening process.

Production of biliverdin by biotransformation of exogenous heme using recombinant Pichia pastoris cells.

Biliverdin, a bile pigment hydrolyzed from heme by heme oxygenase (HO), serves multiple functions in the human body, including antioxidant, anti-inflammatory, and immune response inhibitory activities. Biliverdin has great potential as a clinical drug; however, no economic and efficient production method is available currently. Therefore, the production of biliverdin by the biotransformation of exogenous heme using recombinant HO-expressing yeast cells was studied in this research.

Isolation of antibody by polymer microspheres embedded with E. coli displaying IgG-binding domain.

Antibody purification is an important aspect of quality and cost control in the production process of antibody drugs. In this study, modified E. coli was embedded into polymer microspheres (polyvinyl alcohol/alginate) for antibody separation and the IgG binding domain was displayed on the surface of E.

A new method based on dispersive liquid-liquid microextraction for fat-soluble vitamin determination in serum by LC-MS/MS.

A green and inexpensive pretreatment known as dispersive liquid-liquid microextraction (DLLME) was developed in this assay coupled with the LC-MS/MS method for routine analysis of fat soluble vitamins (FSVs). The technique was performed with methanol as the dispersive solvent and dichloromethane as the extraction solvent. The extraction phase containing FSVs was evaporated to dryness and reconstituted in a mixture of acetonitrile and water.

Genetic fusion of mussel foot protein to ZZ protein improves target detection in solid-phase immunoassays.

In the process of a solid-phase immunoassay, the stability and binding orientation between the antibody and the solid matrix can substantially influence the results. ZZ protein is a modified peptide of the B domain of Staphylococcus aureus protein A, which can bind to the Fc fragment of an antibody. It is often used for oriented immobilization of antibodies during solid-phase immunoassay.

A general strategy for protein affinity-ligand oriented-immobilization and screening for bioactive compounds.

Natural products containing complex mixtures of potentially bioactive compounds are a major source of new drugs, however, conventional screening for active compounds is a time-consuming and inefficient process. Here, we reported that a facile and efficient protein affinity-ligand oriented-immobilization strategy based on the SpyTag/SpyCatcher(ST/SC) chemistry, was used for bioactive compound screening. Two ST-fused model proteins, that is, GFP (green fluorescent protein) and PqsA (a critical enzyme in the quorum sensing pathway of Pseudomonas aeruginosa), were used to verify the feasibility of this screening method.

A preparation strategy for protein-oriented immobilized silica magnetic beads with Spy chemistry for ligand fishing.

Due to the complexity of bioactive ingredients in biological samples, the screening of target proteins is a complex process. Herein, a feasible strategy for directing protein immobilization on silica magnetic beads for ligand fishing based on SpyTag/SpyCatcher (ST/SC)-mediated anchoring is presented. Carboxyl functional groups on the surface of silica-coated magnetic beads (SMBs) were coupled with SC using the 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride/-hydroxysulfosuccinimide method, named SC-SMBs.

Preparation and identification of an anti-nicarbazin monoclonal antibody and its application in the agriculture and food industries.

Background: As a broad-spectrum drug against chicken coccidiosis, nicarbazine is widely used. The international community has made regulations and requirements on the residue limits of nicarbazine metabolites in chicken. The research reports on the detection methods of nicarbazine residues are mainly based on large-scale instruments such as high-performance liquid chromatography (HPLC), liquid chromatography-mass spectrometry-mass spectrometry (LC/MS/MS) and so on.

Preparation and Characterization of Site-Specific Fatty Chain-Modified Recombinant Human Granulocyte Colony Stimulating Factor.

The clinical use of recombinant human granulocyte colony-stimulating factor (rhG-CSF) is limited by its short serum half-life. In this study, a long-acting strategy for site-specific modification of rhG-CSF with 1-pentadecyl-1H-pyrrole-2,5-dione (C15 fatty chain-maleimide, C15-MAL) was studied in mixed DMSO-aqueous solutions. The factors influencing the conjugation reaction were investigated and optimized, and a high yield of the desired product (C15-rhG-CSF) was achieved.

Generation and Characterization of an Anti-diclazuril Monoclonal Antibody and Development of a Diagnostic Enzyme-Linked Immunosorbent Assay for Poultry.

An anti-diclazuril monoclonal antibody (mAb) was developed for use in enzyme-linked immunosorbent assay (ELISA)-based detection of diclazuril with high sensitivity and specificity, which can be used to measure anti-coccidial drug residues. The anti-diclazuril mAb had a half-maximal inhibitory concentration of 0.449-0.

Preparation and properties of -glycosylated chitosan/polyvinyl alcohol hydrogels for use in wound dressings.

Chitosan and its derivatives show potent biocompatibility, biodegradability, antimicrobial activity, hemostatic effects, and wound healing properties. Their application in wound dressings has garnered substantial research interest. In this work, we prepared a drug-loaded hydrogel by mixing -glycosylated chitosan with polyvinyl alcohol (PVA), followed by loading of ofloxacin.

Production of bilirubin by biotransformation of biliverdin using recombinant Escherichia coli cells.

Bilirubin, a natural intermediate in heme degradation, is a valuable Chinese medicine used in more than 50 traditional Chinese medicine (TCM) preparations. At present, bilirubin is mainly produced by extraction from pig bile, but a shortage of the raw material has increased the price, to about US$10,000/kg in the Chinese market. Biliverdin, the precursor of bilirubin, is more abundant and less expensive than bilirubin, but it is not used in TCM.

Predictive Analysis of the Neutralization Activity in Convalescent Plasmas From COVID-19 Recovered Patients in Zhejiang Province, China, January-March, 2020.

Background: Convalescent plasma (CP) transfusion is considered to be the priority therapeutic option for COVID-19 inpatients when no specific drugs are available for emerging infections. An alternative, simple, and sensitive method is urgently needed for clinical use to detect neutralization activity of the CP to avoid the use of inconvenient micro-neutralization assay.

Method: This study aims to explore optimal index in predicting the COVID-19 CP neutralization activity (neutralizing antibody titers, NAb titers) in an indirect ELISA format.

Preparation and characterization of a Schiff-based chitosan-fructose quaternary ammonium salt for medical applications.

The aim of this study was to develop a new chitosan derivative and investigate its effects on fresh tissue healing in rats. A chitosan-fructose Schiff based quaternary ammonium salt (CS = Fru-DEAE) was synthesized for the first time and characterized using FT-IR and HNMR, and the modification rate and the solution properties were studied. A rat wound model was established, and the experimental group was treated using 0.

An update on Wnt signaling pathway in cancer.

Wnt signaling involves many aspects of development, cell biology and physiology. Mutations in the Wnt gene can lead to abnormal embryonic development and cancer formation, including various aspects that affect proliferation, morphogenesis, and differentiation. The occurrence and development of tumors is a complex process involving multiple factors.

A Biotransformation Process for Production of Genistein from Sophoricoside by a Strain of Rhizopus oryza.

Genistein is known to have multiple biological activities and has great potential for use as a preventative medicine and in disease treatment. Genistein can be extracted from plants, but also can be obtained from its glycoside form, sophoricoside, which is more abundant in some plants. Biotransformation by unpurified microbial enzymes has the advantage of low cost and is a preferred method for production of natural compounds.

Construction and application of an electrochemical biosensor based on an endotoxin aptamer.

An electrochemical biosensor that used an aptamer as a biological element was constructed to detect endotoxin. Biolayer interferometry was used to obtain the affinity constant of an aptamer for lipopolysaccharide, which had an equilibrium dissociation constant of 22.9 nM.

Preparation of recombinant human thymic stromal lymphopoietin protein.

Human thymic stromal lymphopoietin (hTSLP) protein plays a central role in inflammation. Characterizing properties of hTSLP requires a recombinant overexpression system that produces correctly folded, active hTSLP. In this report, an efficient overexpression system for the production of hTSLP was developed.

A biotransformation process for the production of cucurbitacin B from its glycoside using a selected Streptomyces sp.

Cucurbitacin B (CuB) and its glycoside, cucurbitacin B 2-o-β-D-glucoside (CuBg), abundantly occur in the pedicels of Cucumis melo. Compared with CuB, CuBg is not efficiently extracted from the pedicels. Furthermore, the anticancer activity of CuBg is lower than that of the aglycone.

Selecting DNA aptamers for endotoxin separation.

Objectives: To select aptamers for endotoxin separation from a 75-nucleotide single-stranded DNA random library using systematic evolution of ligands by exponential enrichment.

Results: After 15 rounds of selection, the final pool of aptamers was specific to endotoxin. Structural analysis of aptamers that appeared more than once suggested that one aptamer can form a G-quartet structure.

Functions of thymic stromal lymphopoietin in non-allergic diseases.

Thymic stromal lymphopoietin (TSLP) is an interleukin 7-like cytokine produced mainly by epithelial cells. Many studies indicate that TSLP contributes to promote T helper (Th) 2 immune responses which are associated with the pathogenesis of allergic inflammatory diseases. Base on the cross-talk between Th2 inflammation and cancers, we will highlight the role of TSLP in the progression of cancers in this review.