HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Arend, W. P. Articles by Mannik, M. Search for Related Content PubMed Articles by Arend, W. P. Articles by Mannik, M.

Determination of Soluble Immune Complex Molar Composition and Antibody Association Constants by Ammonium Sulfate Precipitation¹

From the Department of Medicine, Veterans Administration Hospital, Seattle, Washington 98108 and the Division of Rheumatology, Department of Medicine, University of Washington School of Medicine, Seattle, Washington 98195

Abstract

The interaction between rabbit IgG anti-HSA and HSA was studied by ammonium sulfate precipitation of the complexes formed throughout a wide range of antigen excess. The Ag/Ab molar ratio varied between 0.85 and 1.20 in the range of five to 60 times antigen excess. In greater degrees of antigen excess (up to 500-fold) the molar ratio of the complexes remained at a plateau between 1.20 and 1.25. Identical results were obtained using antibodies isolated by immunoadsorbent techniques or using antibodies in antiserum. The molecular composition of the limiting complexes was primarily Ag₂Ab₂ and Ag₁Ab₁, but a small amount of Ag₂Ab₁ could have been present.

The association constant between anti-HSA and HSA was determined with isolated antibodies and with anti-HSA in antiserum. The association constants were similar, ranging from 2.19 x 10⁷ to 3.20 x 10⁷ liters/mole. However, the values for the association constant were partially dependent upon the absolute amounts of antigen and antibodies present and upon the relative amounts of each.

Footnotes

¹ This work was supported in part by Research Grants AI-10825 and AM-11476, from the United States Public Health Service.

² Recipient of a Clinical Investigator award from the Veterans Administration.