Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Dimeric, trimeric and tetrameric complexes of immunoglobulin G fix complement

J K Wright, J Tschopp, J C Jaton

    The Biochemical Journal
    |June 1, 1980
    PubMed
    Summary
    This summary is machine-generated.

    Related Concept Videos

    You might also read

    Related Articles

    Articles linked to this work by shared authors, journal, and citation graph.

    Sort by
    Same author

    Rapid structural characterisation of a murine monoclonal IgA alpha chain: heterogeneity in the oligosaccharide structures at a specific site in samples produced in different bioreactor systems.

    Journal of biotechnology·1999
    Same author

    Thiol-disulfide redox buffers maintain a structure of immunoglobulin A that is essential for optimal in vitro binding to secretory component.

    Biochimica et biophysica acta·1999
    Same author

    Human free secretory component is composed of the first 585 amino acid residues of the polymeric immunoglobulin receptor.

    FEBS letters·1997
    Same author

    The secalosides, novel tumor cell growth inhibitory glycosides from a pollen extract.

    Journal of natural products·1997
    Same author

    cDNA cloning of a human 100 kDa de-ubiquitinating enzyme: the 100 kDa human de-ubiquitinase belongs to the ubiquitin C-terminal hydrolase family 2 (UCH2).

    FEBS letters·1995
    Same author

    Identification of a prostate inhibitory substance in a pollen extract.

    The Prostate·1995

    Rabbit immunoglobulin G (IgG) oligomers bind to complement components C1 and C1q. Higher order IgG oligomers show increased complement fixation affinity, suggesting a valency of 6-18 protomers for C1 binding.

    Area of Science:

    • Immunology
    • Biochemistry
    • Molecular Biology

    Background:

    • Immunoglobulin G (IgG) is a key antibody in the immune system.
    • The complement system is crucial for innate and adaptive immunity.
    • Understanding IgG-complement interactions is vital for immune response modulation.

    Purpose of the Study:

    • To investigate the binding interactions between purified IgG oligomers (dimers, trimers, tetramers) and complement components C1 and C1q.
    • To determine the effect of IgG oligomerization state on complement fixation affinity and binding mechanisms.
    • To elucidate the valency of C1 for IgG protomers.

    Main Methods:

    • Studied binding of IgG oligomers to C1 and C1q.
    • Analyzed complement fixation using varying concentrations.

    Related Experiment Videos

  • Determined binding constants and assessed cooperative binding mechanisms.
  • Utilized sedimentation-velocity ultracentrifugation to confirm C1q binding.
  • Investigated the effect of reduction on complex stability.

    • Main Results:

    • All IgG oligomers (dimers, trimers, tetramers) fixed complement, with affinity decreasing in the order: tetramer > trimer > dimer.
    • Dimeric IgG showed the strongest concentration-dependent complement fixation.
    • Binding constants (non-cooperative) were approximately 10^6 M^-1 for dimers, 10^7 M^-1 for trimers, and 3 x 10^9 M^-1 for tetramers.
    • Data suggest a maximum valency of 6-18 IgG protomers for C1.
    • C1q binding to dimers was confirmed via ultracentrifugation; reduction dissociated complexes and abolished fixation.

    Conclusions:

    • IgG oligomerization significantly influences complement fixation affinity and mechanism.
    • The valency of C1 for IgG is substantial, ranging from 6 to 18 protomers.
    • These findings provide insights into the molecular basis of immune complex recognition by the complement system.