Antigenic specificity of human serum gamma-globulin samples obtained under conditions of equimolar binding of copper and zinc cations.

Samples of human serum gamma-globulin modified by equimolar binding of copper and zinc cations were obtained using the method of molecular ultrafiltration. Conformation characteristics of the protein were studied by UV spectrophotometry. Immunochemical study included radial immunodiffusion test, direct and sandwich enzyme immunoassays.

Binding of zinc cations to human serum gamma-globulin.

Binding of zinc cations to human serum gamma-globulin was studied by molecular ultrafiltration. The content of free metal in the filtrate was evaluated by reaction with o-phenanthroline. Conformation characteristics of the protein were determined by UV spectrophotometry.

Human serum gamma-globulin binds copper cations.

Binding of copper cations to human serum gamma-globulin was studied using molecular ultrafiltration. The content of free metal in the filtrate was evaluated by the reaction with sodium diethyldithiocarbamate. Conformation characteristics of the protein were evaluated by UV spectrophotometry.

Formation of supramolecular aggregations of gamma-globulin as a metal-dependent process.

The presence of copper cations in the solution of human serum gamma-globulin induced the formation of supramolecular forms of the protein. The intensity of this reaction increased with increasing copper concentration. The mechanisms of g-globulin aggregate formation under normal conditions and the possible role of bivalent metal cations in the regulation of protein effector functions are discussed.