We have generated a single chain antigen binding protein (scFv) recognising morphine. Variable regions of heavy (V(H)) and light (V(L)) chain antibody genes isolated from a murine immune repertoire were connected via a glycine-serine linker and cloned into the expression vector pAK 400. The scFv was produced in Escherichia coli JM83 yielding a functional protein of approximately M(r) 30000. Immunoaffinity chromatography using M3G-BSA-Sepharose column proved most effective for scFv purification. Purity was monitored by SDS-PAGE and Western blotting and the scFv characterised using ELISA and BIAcore. The scFv was capable of specifically binding free morphine in solution and was applicable to real sample analysis in saliva. In order to express a bivalent "minibody" the scFv gene was recloned into a vector containing a gene encoding a helix for dimerisation. The scFv was expressed as a protein of M(r) 75000 and retained its antibody binding capabilities. Cloning the scFv gene into a vector containing the bacterial alkaline phosphatase gene produced a bifunctional molecule, which retained the binding activity of the parental scFv along with the enzymatic activity of alkaline phosphatase.
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http://dx.doi.org/10.1016/s1570-0232(02)00807-3 | DOI Listing |
Food Chem
January 2025
College of Life Science, Shandong Agricultural University, Tai'an 271018, China. Electronic address:
Zearalenone (ZEN) is a widely distributed mycotoxin with potent estrogenic activity. Detecting ZEN is crucial for assessing its potential health risks. This study developed a highly sensitive non-competitive magnetic phage anti-immunocomplex immunoassay (Nc-MPHAIA) for ZEN detection, utilizing the anti-ZEN single-chain variable fragment (ScFv) and anti-immunocomplex peptide (AIcP), both of which were screened using phage display technology.
View Article and Find Full Text PDFBiochem Biophys Res Commun
January 2025
Department of Pharmacology, Life Science and Biopharmaceutical Institution, Shenyang Pharmaceutical University, Shenyang, 110016, Liaoning Province, China. Electronic address:
Agonistic monoclonal antibodies targeting 4-1BB have shown much preclinical promise, but their clinical development has been limited by obvious toxicity or unremarkable efficacy. Here, we generated two humanized anti-B7H3 × 4-1BB bsAbs (HK056-001/002) by fusing an anti-4-1BB scFv to the C-terminus of an anti-B7H3 with an intact Fc fragment from human IgG1 or IgG4. The two bsAbs were able to stimulate the 4-1BB signaling pathway, which was strictly dependent on B7H3 expression.
View Article and Find Full Text PDFJ 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 PDFCell J
January 2025
Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran. Email:
Objective: Colorectal cancer (CRC) is the second leading cause of cancer-related deaths worldwide. Engineered biomolecules can be used as a targeted tool to deliver drugs directly to tumors that reduce the adverse effects of conventional treatments. We aimed to prepare non-targeted oxaliplatin-loaded chitosan nanoparticles (OXPT-CS NPs) and targeted OXPT-CS NPs decorated with cetuximab single-chain variable fragment (scFv) to send both NPs to epidermal growth factor receptor (EGFR) overexpressing HCT 116 cells, a human colorectal carcinoma cell line, for comparing their cytotoxicity.
View Article and Find Full Text PDFCD19-directed chimeric antigen receptor-engineered (CD19 CAR) T-cell therapy elicits high response rates but fails to induce durable responses in most adults with relapsed or refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL). In a previous clinical trial (NCT01865617), we observed anti-CAR immune responses associated with impaired in vivo CAR T-cell expansion after second infusions. Because these CD8+ T-cell responses were predominantly directed at peptides derived from the murine single chain variable fragment (scFv) in the CAR, we conducted a clinical trial investigating the safety and efficacy of CD19 CAR T-cells engineered with a CAR incorporating a fully human scFv (JCAR021) in adults with R/R B-ALL (NCT03103971).
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