Abstract
The number, location, and other characteristics of the antigenic determinants for self-association of IgG-rheumatoid factors (IgG-RF) were examined using the IgG-RF isolated from the plasma of one patient as a model system. Affinity chromatography was employed for isolation of the IgG-RF. Sedimentation equilibrium ultracentrifugation was used to study the various interactions. The antigenic valence of IgG-RF Fc, normal human Fc, and rabbit Fc fragments was two for the interaction with Fab fragments from IgG-RF, as might be expected from the molecular symmetry of IgG. The antigenic valence of intact normal IgG, however, was only one, indicating that when one of the available antigenic determinants interacted with the Fab fragment of IgG-RF, the other determinant becomes sterically inaccessible. Reduction and alkylation, known to increase the flexibility of the hinge region, did not alter the antigenic valence of IgG for Fab fragments of IgG-RF. The antigenic valence of IgG-RF in self-association could not be experimentally determined but must be two to permit the observed concentration-dependent further polymer formation of IgG-RF dimers. Unique antigenic determinants on the Fc fragments of IgG-RF were sought and not found, thus reaffirming the formation of two antigen-antibody bonds as the basis for dimerization of IgG-RF molecules. The pFc’ and Fc’ fragments, representing Cγ3 domains of IgG, failed to show significant interaction with Fab fragments of IgG-RF, indicating that the antigenic determinants were not expressed by the Cγ3 regions but are located either on Cγ2 region or require intact Cγ2 and Cγ3 regions for expression. These conclusions were corroborated by the antigenic valence of one for the Fc(i) fragment, a new papain-generated intermediate fragment of Fc, composed of two intact Cγ3 domains and one intact Cγ2 domain. Normal IgG, because of its valence of one for interaction with IgG-RF, would effectively terminate further polymerization of IgG-RF dimers. This may well in part explain the finding of smaller IgG-RF complexes in the serum than in synovial fluid of patients with rheumatoid arthritis.
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- AMINOFF D. Methods for the quantitative estimation of N-acetylneuraminic acid and their application to hydrolysates of sialomucoids. Biochem J. 1961 Nov;81:384–392. doi: 10.1042/bj0810384. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Allen J. C., Kunkel H. G. Hidden rheumatoid factors with specificity for native gamma globulins. Arthritis Rheum. 1966 Dec;9(6):758–768. doi: 10.1002/art.1780090603. [DOI] [PubMed] [Google Scholar]
- Behnke W. D., Teller D. C., Wade R. D., Neurath H. Hybrid formation of carboxypeptidase A and fraction II of procarboxypeptidase A. Biochemistry. 1970 Oct 13;9(21):4189–4200. doi: 10.1021/bi00823a022. [DOI] [PubMed] [Google Scholar]
- DeRosier D. J., Munk P., Cox D. J. Automatic measurement of interference photographs from the ultracentrifuge. Anal Biochem. 1972 Nov;50(1):139–153. doi: 10.1016/0003-2697(72)90493-9. [DOI] [PubMed] [Google Scholar]
- FLEISCHMAN J. B., PAIN R. H., PORTER R. R. Reduction of gamma-globulins. Arch Biochem Biophys. 1962 Sep;Suppl 1:174–180. [PubMed] [Google Scholar]
- Hymes A. J., Mullinax G. L., Mullinax F. Immunoglobulin carbohydrate requirement for formation of an IgG-IgG complex. J Biol Chem. 1979 May 10;254(9):3148–3151. [PubMed] [Google Scholar]
- KUNKEL H. G., MULLER-EBERHARD H. J., FUDENBERG H. H., TOMASI T. B. Gamma globulin complexes in rheumatoid arthritis and certain other conditions. J Clin Invest. 1961 Jan;40:117–129. doi: 10.1172/JCI104224. [DOI] [PMC free article] [PubMed] [Google Scholar]
- KUNKEL H. G. Zone electrophoresis. Methods Biochem Anal. 1954;1:141–170. doi: 10.1002/9780470110171.ch6. [DOI] [PubMed] [Google Scholar]
- Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
- MARLER E., NELSON C. A., TANFORD C. THE POLYPEPTIDE CHAINS OF RABBIT GAMMA-GLOBULIN AND ITS PAPAIN-CLEAVED FRAGMENTS. Biochemistry. 1964 Feb;3:279–284. doi: 10.1021/bi00890a024. [DOI] [PubMed] [Google Scholar]
- Nardella F. A., Mannik M. Nonimmunospecific protein-protein interactions of IgG: studies of the binding of IgG to IgG immunoadsorbents. J Immunol. 1978 Mar;120(3):739–744. [PubMed] [Google Scholar]
- Natvig J. B., Gaarder P. I., Turner M. W. IgG antigens of the C gamma 2 and C gamma 3 homology regions interacting with rheumatoid factors. Clin Exp Immunol. 1972 Oct;12(2):177–184. [PMC free article] [PubMed] [Google Scholar]
- PORTER R. R. The hydrolysis of rabbit y-globulin and antibodies with crystalline papain. Biochem J. 1959 Sep;73:119–126. doi: 10.1042/bj0730119. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pope R. M., Teller D. C., Mannik M. The molecular basis of self-association of IgG-Rheumatoid factors. J Immunol. 1975 Aug;115(2):365–373. [PubMed] [Google Scholar]
- Pope R. M., Teller D. C., Mannik M. The molecular basis of self-association of antibodies to IgG (rheumatoid factors) in rheumatoid arthritis. Proc Natl Acad Sci U S A. 1974 Feb;71(2):517–521. doi: 10.1073/pnas.71.2.517. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Romans D. G., Tilley C. A., Crookston M. C., Falk R. E., Dorrington K. J. Conversion of incomplete antibodies to direct agglutinins by mild reduction: evidence for segmental flexibility within the Fc fragment of immunoglobulin G. Proc Natl Acad Sci U S A. 1977 Jun;74(6):2531–2535. doi: 10.1073/pnas.74.6.2531. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schrohenloher R. E. Characterization of the gamma-globulin complexes present in certain sera having high titers of anti-gamma-globulin activity. J Clin Invest. 1966 Apr;45(4):501–512. doi: 10.1172/JCI105364. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Seegan G. W., Smith C. A., Schumaker V. N. Changes in quaternary structure of IgG upon reduction of the interheavy-chain disulfide bond. Proc Natl Acad Sci U S A. 1979 Feb;76(2):907–911. doi: 10.1073/pnas.76.2.907. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stage D. E., Mannik M. Covalent binding of molecules to CNBr-activated agarose: parameters relevant to the activation and coupling reactions. Biochim Biophys Acta. 1974 Apr 22;343(2):382–391. doi: 10.1016/0304-4165(74)90102-0. [DOI] [PubMed] [Google Scholar]
- Stone M. J., Metzger H. Binding properties of a Waldenström macroglobulin antibody. J Biol Chem. 1968 Nov 25;243(22):5977–5984. [PubMed] [Google Scholar]
- Teller D. C. Characterization of proteins by sedimentation equilibrium in the analytical ultracentrifuge. Methods Enzymol. 1973;27:346–441. doi: 10.1016/s0076-6879(73)27017-9. [DOI] [PubMed] [Google Scholar]
- Turner M. W., Bennich H. Subfragments from the Fc fragment of human immunoglobulin G. Isolation and physicochemical charaterization. Biochem J. 1968 Mar;107(2):171–178. doi: 10.1042/bj1070171. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Winchester R. J., Agnello V., Kunkel H. G. Gamma globulin complexes in synovial fluids of patients with rheumatoid arthritis. Partial characterization and relationship to lowered complement levels. Clin Exp Immunol. 1970 May;6(5):689–706. [PMC free article] [PubMed] [Google Scholar]