Related Experiment Video

Updated: Jun 29, 2026

Epigenetic Conversion as a Safe and Simple Method to Obtain Insulin-secreting Cells from Adult Skin Fibroblasts
08:45

Epigenetic Conversion as a Safe and Simple Method to Obtain Insulin-secreting Cells from Adult Skin Fibroblasts

Published on: March 18, 2016

Disulfide reduction converts the insulin receptor of human placenta to a low affinity form

S Jacobs, P Cuatrecasas

    The Journal of Clinical Investigation
    |December 1, 1980
    PubMed

    Treatment of human placenta membranes with dithiothrietol (DTT) followed by N-ethylmaleimide results in a 60% reduction in insulin binding. Treatment with N-ethylmaleimide alone has little effect. The decrease in insulin binding that results from DTT treatment is due to a decrease in affinity for insulin, with little change in total receptor number. DTT has similar effects on receptor solubilized from placenta membranes with Triton X-100, indicating that its effects are not attributable to changes in the arrangement of receptors in the membrane. In contrast to placenta membranes, treatment of liver membranes with DTT does not decrease insulin binding. These results suggest that reduction of a critical disulfide bond in insulin receptors from human placenta converts the receptor to a low affinity form.

    More Related Videos

    Measuring Relative Insulin Secretion using a Co-Secreted Luciferase Surrogate05:58

    Measuring Relative Insulin Secretion using a Co-Secreted Luciferase Surrogate

    Published on: June 25, 2019

    Precise Visualization of Insulin Receptors A and B in Murine Brain with an RNA In Situ Hybridization Assay08:34

    Precise Visualization of Insulin Receptors A and B in Murine Brain with an RNA In Situ Hybridization Assay

    Published on: July 15, 2025

    Related Concept Videos

    Protein and Protein Structure02:15

    Protein and Protein Structure

    Proteins are one of the most abundant organic molecules in living systems and have the most diverse range of functions of all macromolecules. Proteins may be structural, regulatory, contractile, or protective. They may serve in transport, storage, or membranes; or they may be toxins or enzymes. Their structures, like their functions, vary greatly. They are all, however, amino acid polymers arranged in a linear sequence.
    A protein's shape is critical to its function. For example, an enzyme can...
    Insulin Secretory Vesicles01:05

    Insulin Secretory Vesicles

    Insulin secretory vesicles release insulin to stimulate blood glucose uptake and regulate carbohydrate metabolism. When the blood glucose levels increase, glucose enters the pancreatic β-islet cells through glucose transporters. Once inside, glucose is metabolized through glycolysis, the citric acid cycle, and the electron transport chain, producing ATP. This increase in ATP concentration closes ATP-sensitive potassium channels, leading to depolarization of the membrane and the opening of...
    Glucose Homeostasis: Pancreatic Islets and Insulin Secretion01:27

    Glucose Homeostasis: Pancreatic Islets and Insulin Secretion

    The pancreatic islets comprising only 1%-2% of the volume are highly vascularized and innervated mini-organs. They contain five endocrine cell types, including β cells that secrete insulin, which is synthesized as a single polypeptide chain, preproinsulin, processed to proinsulin, and finally to insulin and C-peptide. This process is complex and regulated, involving the Golgi complex, the endoplasmic reticulum, and the secretory granules of the β cell.
    Insulin and C-peptide are co-secreted in...
    Insulin: The Receptor and Signaling Pathways01:28

    Insulin: The Receptor and Signaling Pathways

    Insulin action is mediated through a receptor tyrosine kinase, akin to the IGF-1 receptor. The number of receptors per cell varies significantly, from 40 on erythrocytes to 300,000 on adipocytes and hepatocytes. The insulin receptor consists of linked α/β subunit dimers, forming a heterotetramer glycoprotein with two extracellular α subunits and two β subunits spanning the membrane. The α subunits inhibit the inherent tyrosine kinase activity of the β subunits, but this inhibition is released...
    Insulin: Biosynthesis, Chemistry, and Preparation01:25

    Insulin: Biosynthesis, Chemistry, and Preparation

    The endoplasmic reticulum (ER) of pancreatic β-cells synthesizes preproinsulin, which consists of a signal peptide, A and B chains, and a C-peptide. Preproinsulin is then cleaved and folded into proinsulin, which translocates to the Golgi apparatus for sorting and packaging into secretory granules. In these granules, enzymatic clipping generates insulin and C-peptide.
    Damage or functional impairment of β-cells inhibits insulin production, leading to diabetes. Diabetes treatment primarily uses...
    Glucagon-like Receptor Agonists01:24

    Glucagon-like Receptor Agonists

    Incretins include glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), which stimulate insulin secretion post-meals. In type 2 diabetes, GIP's efficacy is reduced, making GLP-1 a viable drug target. GIP originates from preproGIP.
    GLP-1, when administered in high doses intravenously, triggers insulin secretion, inhibits glucagon release, slows gastric emptying, reduces food intake, and restores normal insulin secretion. However, its rapid inactivation by the...