Video Experimental Relacionado
Updated: Jul 13, 2026
10:36
Prescribed 3-D Direct Writing of Suspended Micron/Sub-micron Scale Fiber Structures via a Robotic Dispensing System
Published on: June 12, 2015
Estructura de la columna vertebral beta cruzada de las fibrillas tipo amiloide
Rebecca Nelson1, Michael R Sawaya, Melinda Balbirnie
1Howard Hughes Medical Institute, UCLA-DOE Institute for Genomics and Proteomics, Box 951570, UCLA, Los Angeles, California 90095-1570, USA.
Nature
|June 10, 2005
Resumen
Los investigadores determinaron la estructura atómica de las fibrillas tipo amiloide formadas por un segmento de proteína de levadura. Esta estructura revela cómo estos agregados de proteínas obtienen estabilidad y auto-semilla, ofreciendo información sobre enfermedades como el Alzheimer.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Biología Estructural Biología estructural.
- Biología Molecular Biología Molecular
Sus antecedentes:
- Las proteínas solubles pueden convertirse en fibrillas insolubles similares al amiloide con características compartidas.
- Las fibrillas amiloides están implicadas en enfermedades neurodegenerativas como la enfermedad de Alzheimer.
- La formación de amiloide puede estudiarse in vitro y está relacionada con la transmisión de priones.
Objetivo del estudio:
- Para determinar la estructura atómica de la columna vertebral cruzada-beta en las fibrillas tipo amiloide formadas por un péptido de proteína de levadura Sup35.
- Aclarar los mecanismos moleculares subyacentes a la estabilidad de las fibras amiloides, la auto-siembra y el polimorfismo.
Principales métodos:
- Formación de fibrillas y microcristales de tipo amiloide a partir de un segmento péptido de siete residuos de la proteína de levadura Sup35.
- Determinación de la estructura atómica de la columna vertebral beta cruzada utilizando técnicas como la cristalografía de rayos X (implicado).
Principales resultados:
- La estructura atómica revela una arquitectura de doble hoja beta para la columna vertebral beta cruzada.
- Cada hoja beta está compuesta por segmentos paralelos apilados en registros.
- Una cremallera estérica formada por cadenas laterales sobresalientes estabiliza la estructura de doble hoja beta a través de la unión de hidrógeno.
Conclusiones:
- La estructura determinada explica la notable estabilidad de las fibrillas amiloides.
- Los hallazgos proporcionan información sobre las propiedades de auto-siembra de la formación de amiloide.
- El estudio arroja luz sobre la base estructural de la naturaleza polimórfica de las fibrillas amiloides.
Videos de Conceptos Relacionados
02:15Protein 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...
A protein's shape is critical to its function. For example, an enzyme can...
01:19The Structure of Intermediate Filaments
The intermediate filaments are one of three widely studied cytoskeletal filaments. They are so named as their diameter (10 nm) is in between that of microfilaments (7 nm) and the microtubules (25 nm). These filaments are highly stable and can remain intact when exposed to high salt concentrations and detergents. These filaments are responsible for providing stability and mechanical support to the cells. They also help in cell adhesion and maintaining tissue integrity.
Intermediate filaments...
Intermediate filaments...
01:11Fibril-associated Collagen
Fibril-associated collagens are a type of collagens present in the extracellular matrix with interrupted triple helices or FACIT (Fibril-associated collagens interrupted triple-helices). FACIT help connect and attach the collagen fibrils with each other as well as with other proteins of the extracellular matrix.
For example, the type II collagen fibrils in cartilage have covalently bound type IX fibril-associated collagens at regular intervals. Other types of fibril-associated collagens are...
For example, the type II collagen fibrils in cartilage have covalently bound type IX fibril-associated collagens at regular intervals. Other types of fibril-associated collagens are...
01:05Type IV Collagen of Basal Lamina
Type IV collagen is a 400 nm long, network-forming collagen that acts as a barrier between the epithelial and endothelial cells. Type IV collagen forms the backbone of the basement membrane by scaffolding with laminin, entactin, proteoglycans, and fibronectin. Apart from rendering structural support to the basement membrane, it also helps entail signaling potentials necessary for both pathological and physiological functions.
A type IV collagen molecule has six alpha chains which can exist in...
A type IV collagen molecule has six alpha chains which can exist in...
01:30General Structure of a Vertebra
A typical vertebra, with the exception of the sacrum and coccyx, consists of a body, a vertebral arch, and seven different projections termed processes. The anterior portion of the vertebrae, the body, supports about half the body’s weight. The vertebral bodies progressively increase in size and thickness from the cervical region to the lumbar region of the vertebral column. The intervertebral discs present between the bodies of adjacent vertebrae firmly unites them, forming a continuous column.
00:55Fibrous Proteins
Fibrous proteins are either long and narrow proteins or assemble to form long and thin structures. They contain repetitive units and usually consist of either alpha helices or beta sheets and, in rare cases, a mix of both. The amino acids in the primary structure often consist of repeating amino acid sequences. The role of fibrous proteins is primarily structural. Many are located in the extracellular matrix and are present in connective tissues to impart strength and joint mobility. They are...