In this article, we reported the development of a biotinylated single-chain variable fragment (scFv) antibody based indirect competitive enzyme-linked immunosorbent assay (IC-ELISA) for parathion-methyl (PM) detection. Firstly, a phage display library was generated using a pre-immunized BALB/C mouse against a specific hapten of PM. After four rounds of panning, the scFv gene fragments were transferred into a secreted expression vector. Then, the scFv antibodies were secreted expressed and screened by IC-ELISA against PM. The selected scFv antibody was fused with a biotin acceptor domain (BAD) and inserted into pET-28a(+) vector for high-level expression in Escherichia coli BL2 (DE3). After optimizing expression conditions, the scFv-BAD antibody was expressed as a soluble protein and biotinylated in vitro by the E. coli biotin ligase (BirA). Subsequently, the biotinylated scFv-BAD antibody was purified with a high yield of 59.2 ± 3.7 mg/L of culture, and was characterized by SDS-PAGE and western blotting. Finally, based on the biotinylated scFv-BAD, a sensitive IC-ELISA for detection of PM was developed, and the 50% inhibition value (IC50) of PM was determined as 14.5 ng/mL, with a limit of detection (LOD, IC10) of 0.9 ng/mL. Cross-reactivity (CR) studies revealed that the scFv antibody showed desirable specificity for PM.
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http://dx.doi.org/10.1016/j.pep.2016.05.005 | DOI Listing |
J Biol Chem
January 2025
Institute of Biochemistry and Molecular Biology II, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University, Düsseldorf, Germany. Electronic address:
Recently, we phenocopied Interleukin (IL-)6 signaling using the dimerized single-chain variable fragment (scFv) derived from the respiratory syncytial virus (RSV) IgG1-antibody Palivizumab (PLHFc) to activate a Palivizumab anti-idiotypic nanobody (AIP)-gp130 receptor fusion protein. Palivizumab was unable to activate STAT3 signaling, so we aimed to create a similar ligand capable of triggering this pathway. Here, we created three variants of the ligand called PLH0Fc, PLH4Fc and PLH8Fc by shortening the spacer region connecting PLH and Fc from 23 amino acids in PLHFc to 0 amino acids or expanding it by rigid linkers of 4 or 8 alpha helical loops, respectively.
View Article and Find Full Text PDFAnalyst
January 2025
College of Veterinary Medicine, Institute of Comparative Medicine, Yangzhou University, Yangzhou 225009, China.
The M13 phage carries approximately 5 copies of the pIII protein, each of which is capable of displaying a single-chain variable fragment (scFv) that targets a specific antigen. This feature enables the M13 phage to be widely employed in the construction of scFv libraries, thereby facilitating the identification of antibodies with high specificity and affinity for target antigens. In this study, mice were immunized three times with (strain C50041) to induce diverse antibodies.
View Article and Find Full Text PDFSci Adv
January 2025
Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
Small extracellular vesicles (sEVs) are nanosized vesicles. Death receptor 5 (DR5) mediates extrinsic apoptosis. We engineer DR5 agonistic single-chain variable fragment (scFv) expression on the surface of sEVs derived from natural killer cells.
View Article and Find Full Text PDFJ Transl Med
January 2025
Department of Medical Oncology, Division of Life Sciences and Medicine, The First Affiliated Hospital of USTC, University of Science and Technology of China, Anhui Provincial Cancer Hospital, Hefei, 230031, Anhui, China.
Background: Agonistic monoclonal antibodies targeting 4-1BB/CD137 have shown preclinical promise, but their clinical development has been limited by severe liver toxicity or limited efficacy. Therefore, a safe and efficient immunostimulatory molecule is urgently needed for cancer immunotherapy.
Methods: A novel anti-MSLN×4-1BB bispecific antibody (bsAb) was generated via antibody engineering, and its affinity and activity were detected via enzyme-linked immunosorbent assay (ELISA), flow cytometry, and T-cell activation and luciferase reporter assays.
Matrix Biol
February 2025
Department of Life Sciences, Ewha Womans University, Seoul 03760, South Korea. Electronic address:
Disrupting the interaction between matrix metalloproteinase-7 (MMP-7) and syndecan-2 (SDC-2) can yield anticancer effects in colon cancer cells. Here, a single-chain variable fragment (scFv) targeting the pro-domain of MMP-7 was generated as a potential candidate anticancer agent. Among the generated scFvs, those designated 1B7 and 1C3 showed the strongest abilities to inhibit the ability of MMP-7 pro-domain to directly interact with SDC-2 in vitro and decrease the cancer activities of human HT29 colon adenocarcinoma cells.
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