Related Experiment Video

Updated: Jul 12, 2026

Biotinylated Cell-penetrating Peptides to Study Intracellular Protein-protein Interactions
10:26

Biotinylated Cell-penetrating Peptides to Study Intracellular Protein-protein Interactions

Published on: December 20, 2017

Characterization of an islet carboxypeptidase B involved in prohormone processing

R B Mackin, B D Noe

    Endocrinology
    |February 1, 1987
    PubMed

    More Related Videos

    Visualization of Endogenous Mitophagy Complexes In Situ in Human Pancreatic Beta Cells Utilizing Proximity Ligation Assay08:40

    Visualization of Endogenous Mitophagy Complexes In Situ in Human Pancreatic Beta Cells Utilizing Proximity Ligation Assay

    Published on: May 2, 2019

    Human Pseudoislet System for Synchronous Assessment of Fluorescent Biosensor Dynamics and Hormone Secretory Profiles08:04

    Human Pseudoislet System for Synchronous Assessment of Fluorescent Biosensor Dynamics and Hormone Secretory Profiles

    Published on: November 3, 2023

    Related Concept Videos

    Overview of Secretory Vesicles01:33

    Overview of Secretory Vesicles

    Secretory vesicles, also known as dense core vesicles (DCVs), are membrane-bound vesicles that transport secretory proteins, such as hormones or neurotransmitters. Regulated secretory vesicles transport proteins from the trans-Golgi network to the exterior of the cell. Proteins present in regulated secretory vesicles are required to be rapidly exocytosed in large amounts upon a specific stimulus.
    Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
    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...
    Allosteric Proteins-ATCase01:19

    Allosteric Proteins-ATCase

    Binding sites linkages can regulate a protein's function.  For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor.
    Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to  N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
    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: 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...
    Production of Pharmaceuticals01:30

    Production of Pharmaceuticals

    Industrial insulin production uses genetically engineered E. coli expressing a proinsulin gene controlled by a tryptophan promoter and containing a methionine linker for later cleavage. The cells also carry ampicillin resistance for selective growth. Seed cultures are stored at −80 °C and production begins by thawing a small amount to inoculate starter cultures, which are progressively scaled to a 50,000-L bioreactor. In the bioreactor, E. coli grow in nutrient-rich media under sterile, tightly...