Insulin--receptor interactions in adipose tissue cells: direct measurement and properties.
TLDR
The total binding capacity of fat cells is quantitatively recovered in the particulate fraction after homogenization, and the insulin-cell receptor interaction is a simple dissociable process involving a homogeneous species probably present exclusively in the cell membrane.Abstract:
An assay system is described for measurement of specific binding of [125I]insulin to intact fat cells and membrane fractions from such cells. The binding is time- and temperature-dependent and saturable with respect to insulin; the bound insulin is displaced by native insulin but not by oxidized or reduced insulin or by a number of other peptide hormones. A maximum of about 11,000 molecules of insulin can bind per cell. The insulin-receptor association is a bimolecular reaction with a rate constant of 1.5 × 107 M-1 sec-1, while the dissociation is a strictly first-order process with a rate constant of 7.4 × 10-4 sec-1. A dissociation constant of 5.0 × 10-11 M can be calculated from these rate constants, whereas a value of 6.1 × 10-11 M is obtained on the basis of enhancement of glucose oxidation. Complex formation does not result in chemical change or inactivation of insulin or receptor. The total binding capacity of fat cells is quantitatively recovered in the particulate fraction after homogenization. The insulin-cell receptor interaction is a simple dissociable process involving a homogeneous species probably present exclusively in the cell membrane.read more
Citations
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Intracellular aspects of the process of protein synthesis
TL;DR: The title of the Nobel Lecture of George Palade (1 August, p. 347) should have been "Intracellular aspects of the process of protein secretion."
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The labelling of proteins to high specific radioactivities by conjugation to a 125I-containing acylating agent. Application to the radioimmunoassay
A. E. Bolton,William M. Hunter +1 more
TL;DR: With some antisera the immunoreactivity of the antigen was diminished by the introduction of a single I atom into the tyrosyl groups, whereas antigen containing a single (125)I-labelled 3-(4-hydroxyphenyl)propionamide group showed the same immunore activity as the unmodified antigen.
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Binding and Degradation of Low Density Lipoproteins by Cultured Human Fibroblasts COMPARISON OF CELLS FROM A NORMAL SUBJECT AND FROM A PATIENT WITH HOMOZYGOUS FAMILIAL HYPERCHOLESTEROLEMIA
TL;DR: It is raised that a prerequisite for the regulation of cholestero-genesis in cultured fibroblasts is the initial binding of low density lipoproteins to the high affinity surface receptor sites and that a defect in this process represents the primary genetic abnormality in the disorder familial hypercholesterolemia.
Journal ArticleDOI
125I-labeled human epidermal growth factor. Binding, internalization, and degradation in human fibroblasts.
TL;DR: The data are consistent with a mechanism in which 125I-hEGF initially is bound to the cell surface and subsequently is internlized before degradation, and the binding capacity of these cells is restored by incubation in a serum-containing medium.
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Banting Lecture. Insulin action, diabetogenes, and the cause of type II diabetes.
TL;DR: The person who passes urine which is exceedingly sweet, cool, slightly viscid, turbid, and resembling the juices of the sugarcane … suffers from glycosuria.
References
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Preparation of Iodine-131 Labelled Human Growth Hormone of High Specific Activity
W M Hunter,F. C. Greenwood +1 more
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