Dynamics of Inter-heavy Chain Interactions in Human Immunoglobulin G (IgG) Subclasses Studied by Kinetic Fab Arm Exchange
| العنوان: | Dynamics of Inter-heavy Chain Interactions in Human Immunoglobulin G (IgG) Subclasses Studied by Kinetic Fab Arm Exchange |
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| المؤلفون: | Onno Bende, Samira Absalah, Anna M. Davies, Gestur Vidarsson, Rob C. Aalberse, Pleuni Ooijevaar-de Heer, Brian J. Sutton, Theo Rispens |
| المساهمون: | Landsteiner Laboratory |
| المصدر: | The Journal of Biological Chemistry Journal of biological chemistry, 289(9), 6098-6109. American Society for Biochemistry and Molecular Biology Inc. |
| سنة النشر: | 2014 |
| مصطلحات موضوعية: | Protein Structure, Stereochemistry, Biochemistry, Dissociation (chemistry), Antibodies, Structural variation, 03 medical and health sciences, Immunoglobulin Fab Fragments, Antibody Engineering, 0302 clinical medicine, Protein structure, Structural Biology, Fluorescence Resonance Energy Transfer, Humans, Molecular Biology, 030304 developmental biology, chemistry.chemical_classification, 0303 health sciences, biology, Cell Biology, Sulfhydryl, Allotype, 3. Good health, Amino acid, Förster resonance energy transfer, chemistry, Structural biology, Immunoglobulin G, Protein Structure and Folding, biology.protein, Thermodynamics, Antibody, Immunoglobulin Heavy Chains, 030215 immunology |
| الوصف: | Background: Fab arm exchange requires weak interactions between CH3 domains, such as in human IgG4. Results: CH3-CH3 interactions differ >1,000,000-fold between human subclasses and allotypes due to variations Lys/Asn-392, Val/Met-397, and Lys/Arg-409. Conclusion: For IgG2 and IgG3, but not IgG1, hinge disulfide bonds are essential to prevent half-molecule dissociation. Significance: Subclass/allotype variation in the CH3 domain can alter antibody stability and functionality. Interdomain interactions between the CH3 domains of antibody heavy chains are the first step in antibody assembly and are of prime importance for maintaining the native structure of IgG. For human IgG4 it was shown that CH3-CH3 interactions are weak, resulting in the potential for half-molecule exchange (“Fab arm exchange”). Here we systematically investigated non-covalent interchain interactions for CH3 domains in the other human subclasses, including polymorphisms (allotypes), using real-time monitoring of Fab arm exchange with a FRET-based kinetic assay. We identified structural variation between human IgG subclasses and allotypes at three amino acid positions (Lys/Asn-392, Val/Met-397, Lys/Arg-409) to alter the strength of inter-domain interactions by >6 orders of magnitude. Each substitution affected the interactions independent from the other substitutions in terms of affinity, but the enthalpic and entropic contributions were non-additive, suggesting a complex interplay. Allotypic variation in IgG3 resulted in widely different CH3 interaction strengths that were even weaker for IgG3 than for IgG4 in the case of allotype G3m(c3c5*/6,24*), whereas G3m(s*/15*) was equally stable to IgG1. These interactions are sufficiently strong to maintain the structural integrity of IgG1 during its normal life span; for IgG2 and IgG3 the inter-heavy chain disulfide bonds are essential to prevent half-molecule dissociation, whereas the labile hinge disulfide bonds favor half-molecule exchange in vivo for IgG4. |
| اللغة: | English |
| تدمد: | 0021-9258 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c5ce899ebd721637ba0a3c95f62d0e00 https://doi.org/10.1074/jbc.m113.541813 |
| حقوق: | OPEN |
| رقم الأكسشن: | edsair.doi.dedup.....c5ce899ebd721637ba0a3c95f62d0e00 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 00219258 |
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