Video Experimental Relacionado
Updated: Jun 22, 2026
05:48
Rapid Generation of Amyloid from Native Proteins In vitro
Published on: December 5, 2013
Los amiloides funcionales como almacenamiento natural de hormonas peptídicas en los gránulos secretores de la
Samir K Maji1, Marilyn H Perrin, Michael R Sawaya
1Laboratory of Physical Chemistry, Eidgenössische Technische Hochschule (ETH) Zürich, Wolfgang-Paulistrasse 10, CH-8093 Zürich, Switzerland.
Science (New York, N.Y.)
|June 23, 2009
Resumen
Los amiloides funcionales son agregados de proteínas con funciones biológicas normales. Este estudio revela que las hormonas peptídicas y proteicas en los gránulos secretores endocrinos adoptan estructuras similares a las amiloides, contribuyendo a la fisiología normal.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Biología celular Biología celular.
- Endocrinología Endocrinología.
Sus antecedentes:
- Los agregados amiloides, caracterizados por estructuras cruzadas de hojas beta, están vinculados a enfermedades como el Alzheimer.
- Sin embargo, los amiloides también cumplen funciones normales, ejemplificadas por priones de hongos y Pmel17 de mamíferos en la pigmentación.
Objetivo del estudio:
- Investigar la conformación estructural de las hormonas peptídicas y proteicas dentro de los gránulos secretores endocrinos.
- Para determinar si estas hormonas adoptan estructuras similares a las amiloides y explorar su relevancia fisiológica.
Principales métodos:
- Análisis del almacenamiento de la hormona proteína / péptido en gránulos secretores.
- Caracterización estructural utilizando técnicas sensibles a las conformaciones de hoja beta cruzada (detalles no proporcionados en el resumen).
Principales resultados:
- Los péptidos y las hormonas proteicas dentro de los gránulos secretores exhiben una conformación rica en hojas beta cruzadas tipo amiloide.
- Esta característica estructural se conserva en el sistema endocrino, incluida la glándula pituitaria.
Conclusiones:
- Las hormonas almacenadas en gránulos secretores adoptan conformaciones amiloides funcionales.
- Estos amiloides funcionales juegan un papel en la fisiología normal de las células y tejidos endocrinos.
Videos de Conceptos Relacionados
03:03Amyloid Fibrils
Amyloid fibrils are aggregates of misfolded proteins. Under most circumstances, misfolded proteins are either refolded by chaperone proteins or degraded by the proteasome. However, in the case of a mutation or a disease, these proteins can accumulate to form large clusters and often further assemble to form elongated fibers, called fibrils.
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining, normally used to...
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining, normally used to...
03:03Amyloid Fibrils
Amyloid fibrils are aggregates of misfolded proteins. Under most circumstances, misfolded proteins are either refolded by chaperone proteins or degraded by the proteasome. However, in the case of a mutation or a disease, these proteins can accumulate to form large clusters and often further assemble to form elongated fibers, called fibrils.
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining, normally used to...
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining, normally used to...
01:27Glucose 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 and C-peptide are co-secreted in...
01:05Insulin 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...
01:33Overview 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...
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
01:23Alzheimer Disease ll: Pathophysiology
Alzheimer disease involves structural changes in the brain that begin long before symptoms appear. The most distinctive features are extracellular neuritic plaques and intracellular neurofibrillary tangles.Neuritic plaques form in the cerebral cortex and around blood vessels. These plaques contain a dense core of beta-amyloid (Aβ)—a toxic protein fragment that clumps outside neurons. The core is surrounded by damaged neuronal extensions, as well as reactive astrocytes and microglia. Abnormal...