Modulation of binding and bioactivity of insulin by anti-insulin antibody: relation to possible role of receptor self-aggregation in hormone action

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作者：

Yoram Shechter， Kwen-Jen Chang， Steven Jacobs and Pedro Cuatrecasas

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摘要：

Incubation of physiological concentrations of125I-labeled insulin with liver membranes in the presence of anti-insulin IgG results in a 7- to 15-fold increase in the specific binding of the hormone. The low-affinity/high-capacity binding sites are replaced by an apparently homogeneous class of high-affinity sites, and the nonlinear Statchard plots are converted to linear plots without a change in the maximum number of binding sites. Similarly, the binding of insulin to receptors in 3T3 fibroblasts is increased substantially in the presence of anti-insulin antibody, and the biological activity of subactive concentrations of insulin is enhanced by antibody in these cells. However, the affinity of125I-labeled epidermal growth factor (EGF) in fibroblasts is not affected by anti-EGF IgG. In adipocytes anti-insulin IgG in the same concentration range only inhibits the binding of insulin and suppresses insulin-mediated glucose oxidation. Monovalent Fab′fragments from anti-insulin IgG inhibit the binding of the hormone, indicating that the enhancement of binding in liver membranes and fibroblasts requires the bivalency of the antibody.

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关键词：

Biochemistry Microaggregation Epidermal growth factor Receptor redistribution Fibroblasts Adipocytes

DOI：

10.1073/pnas.76.6.2720

被引量：

255

年份：

1979