Asymmetric disposition of Fab arms in the structures solved for the broadly neutralizing monoclonal antibody (nmAb) IgG1 b12 raised the question of whether the unusual shape observed for b12 is common for all IgG1 mAbs or if there is a difference in the overall shape of nmAbs versus non-nmAbs. We compared small angle x-ray scattering (SAXS) data-based models and limited proteolysis profiles of some IgG1 mAbs known to be having and lacking HIV-1 neutralizing potency. In non-nmAbs, the Fab arms were found to be symmetrically disposed in space relative to central Fc, but in most nmAbs, the Fab arms were asymmetrically disposed, as seen for IgG1 b12. The only exceptions were 2G12 and 4E10, where both Fab arms were closed above Fc, suggesting some Fab-Fc and/or Fab-Fab interaction in the nmAbs that constrained extension of the Fab-Fc linker. Interestingly, these observations were correlated with differential proteolysis profiles of the mAbs by papain. Under conditions when papain could cut both Fab arms of non-nmAbs, only one Fab arm could be removed from neutralizing ones (except for 2G12 and 4E10). Chromatography and small angle x-ray scattering results of papain-digested products revealed that 1) the Fab-Fc or Fab-Fab interactions in unliganded mAbs are retained in digested products, and 2) whereas anti-gp120 non-nmAbs could bind two gp120 molecules, nmAbs could bind only one gp120. Additional experiments showed that except for 2G12 and 4E10, unopen shapes of nmAbs remain uninfluenced by ionic strength but can be reversibly opened by low pH of buffer accompanied by loss of ligand binding ability.
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http://dx.doi.org/10.1074/jbc.M114.563486 | DOI Listing |
Antib Ther
January 2025
Biologics Innovation Institute, Shanghai Jemincare Pharmaceutical Co., Ltd., Lane 535, Huanqiao Road, Pudong New Area, Shanghai 201315, China.
Background: Therapeutic antibody drugs targeting the PD-1 pathway are generally characterized by relatively low response rates and susceptibility to drug resistance during clinical application. Therefore, there is an urgent need for alternative therapeutic strategies to increase the immune response rate. Bispecific antibodies co-targeting PD-1 and PD-L1 may have greater potential to improve the efficacy of the immune checkpoint pathway.
View Article and Find Full Text PDFACS Nano
January 2025
Institute of Biomedical Engineering, University of Toronto, Toronto M5S 2E3, Canada.
Immune complexes (ICs), formed via antibody (Ab)-antigen (Ag) binding, trigger diverse immune responses, which are critical for natural immunity and have uses for vaccines and immunotherapies. While IC-elicited immune responses depend on its structure, existing methods for IC synthesis produce heterogeneous assemblies, which limits control over their cellular interactions and pharmacokinetics. In this study, we demonstrate the use of DNA origami to create synthetic ICs with defined shape, size, and solubility by displaying Ags in prescribed spatial patterns.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
December 2024
Therapeutics Development and Supply, Analytical Development - Janssen Research & Development, LLC, Malvern, PA, USA.
Bispecific antibodies have a wide range of applications in cancer immunotherapy, some of which are manufactured by controlled Fab-arm exchange requiring the reductant 2-mercaptoethylamine (2-MEA). As a process impurity, monitoring the residual 2-MEA in bispecific antibody drug product process development is needed. A novel reversed phase-high performance liquid chromatography (RP-HPLC) method for measurement of residual 2-MEA that uses 7-fluorobenzofurazan-4-sulfonic acid ammonium salt (SBD-F) as a fluorescent-detection tag in drug product formulations containing high concentrations of arginine has been developed.
View Article and Find Full Text PDFInjury
December 2024
Department of Medicine at the School of Medicine, University of Alabama at Birmingham (UAB) Birmingham, AL, 35233, USA; Medicine Service, Michale E. DeBakey VA Medical Center, 2002 Holcombe Blvd, Houston, TX, 77030, USA; Department of Medicine, Baylor College of Medicine, 7200 Cambridge Street, Houston, TX, 77030, USA. Electronic address:
Introduction: We evaluated the association of patient sex with in-patient mortality and discharge disposition after primary total hip arthroplasty (THA) for hip fracture in the U.S.
Methods: Using the 2016-2019 U.
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