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. 1971 Nov;68(11):2730–2733. doi: 10.1073/pnas.68.11.2730

Homotropic Cooperative Binding of the First Component of Guinea Pig Complement to Rabbit IgG-Erythrocyte Complexes: A Possible Allosteric Effect*

James J Thompson 1, Louis G Hoffmann 1
PMCID: PMC389511  PMID: 5288251

Abstract

Binding of the activated first component of guinea pig complement to immune complexes formed between dinitrophenylated erythrocytes and rabbit IgG antibody to 2,4-dinitrophenylhapten has been studied quantitatively. Cooperative binding was observed; it in volves no interactions between the domains on the erythrocyte surface that bind the activated first component of complement, or between the activated complement molecules in solution. By curve-fitting methods, we find that the data are consistent with an allosteric model, which assumes 10 binding sites per domain, a low allosteric equilibrium constant, and virtually exclusive binding to one of the isomers.

Keywords: binding sites; 2,4-dinitrophenol; sensitized erythrocytes; binding domain

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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