Video Experimental Relacionado
Updated: Dec 24, 2025
09:35
Real Time Measurements of Membrane Protein:Receptor Interactions Using Surface Plasmon Resonance SPR
Published on: November 29, 2014
23.3K
Un transportador ABC micobacteriano media la absorción de compuestos hidrófilos
S Rempel1,2, C Gati3,4, M Nijland1
1Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Groningen, The Netherlands.
Nature
|April 17, 2020
Resumen
Mycobacterium tuberculosis utiliza Rv1819c para el transporte de vitamina B12 (cobalamina), a pesar de su estructura de exportador. Este hallazgo revela Rv1819c como un transportador multi-solute crucial para la patogénesis de la tuberculosis.
Área de la Ciencia:
- Microbiología
- Biología estructural
- La bioquímica
Sus antecedentes:
- Mycobacterium tuberculosis (Mtb) causa tuberculosis y puede sintetizar vitamina B12 (cobalamina), pero la absorción de cobalamina está relacionada con la patogénesis.
- Mtb carece de transportadores de cobalamina caracterizados, sin embargo, Rv1819c es esencial para la absorción de cobalamina, a pesar de su pliegue de exportación de cassette de unión al ATP (ABC).
Objetivo del estudio:
- Para aclarar la estructura y la función de la proteína Rv1819c en Mycobacterium tuberculosis.
- Conciliar las pruebas contradictorias sobre el papel de Rv1819c en el transporte de cobalamina y su predicción estructural como exportador de ABC.
Principales métodos:
- Cristalografía de rayos X para determinar las estructuras 3D de Rv1819c.
- Análisis bioinformático de la secuencia de aminoácidos Rv1819c y características estructurales.
- Ensayos funcionales para evaluar las capacidades de transporte de Rv1819c para la cobalamina y la bleomicina.
Principales resultados:
- Las estructuras confirman que Rv1819c posee un pliegue exportador ABC.
- Se identificó una gran cavidad llena de agua (7.700 Å3) dentro de Rv1819c, lo que facilita el transporte.
- Rv1819c demostró la capacidad de transportar tanto cobalamina como bleomicina, que son compuestos hidrófilos estructuralmente distintos.
Conclusiones:
- Rv1819c funciona como un transportador multi-solute para las moléculas hidrófilas.
- Este transportador es análogo a los exportadores de fármacos múltiples de la familia de transportadores ABC.
- La capacidad de transporte dual de Rv1819c tiene implicaciones para comprender la patogénesis de la tuberculosis y las posibles estrategias terapéuticas.
Videos de Conceptos Relacionados
01:27ABC Transporters: Importer
3.3K
ATP-binding cassette or ABC transporters are a class of ATP-driven pumps that hydrolyze ATP to move solutes across the membrane. They can be grouped into importers and exporters. While exporters are present in all domains of life, importers exist only in bacteria and some plants.
In bacteria, based on the number of transmembrane helices and the chemical nature of their substrates, the ABC importers can be divided into three types:
In bacteria, based on the number of transmembrane helices and the chemical nature of their substrates, the ABC importers can be divided into three types:
3.3K
01:31ABC Transporters: Exporter
6.1K
ATP-binding cassette or ABC transporter is the largest superfamily of integral membrane proteins. The transporters have transmembrane-binding domains (TMDs) and nucleotide-binding domains (NBDs). The TMDs are specific to their substrates, whereas the NBDs are similar to engines that complete ATP hydrolysis to complete the substrate transport. They can be full transporters consisting of two TMDs and NBDs, half transporters with one TMD and NBD, while some encoded with a single TMD or NBD are...
6.1K
01:19Drug Absorption Mechanism: Carrier-Mediated Membrane Transport
5.5K
Certain large, lipid-insoluble drug molecules that resemble amino acids, peptides, or glucose, require specialized carrier proteins to facilitate their diffusion across cell membranes. This transport can occur through either facilitated diffusion, which does not require energy input, or active transport, which does require energy input.
Facilitated diffusion is a passive process that utilizes human Solute Carrier (SLC) transporters. These transporters bind to the drug, undergo structural...
Facilitated diffusion is a passive process that utilizes human Solute Carrier (SLC) transporters. These transporters bind to the drug, undergo structural...
5.5K
01:06Carrier-Mediated Transport
902
Carrier-mediated transport is a pivotal process in drug absorption, particularly for lipid-insoluble drugs, and encompasses facilitated diffusion and active transport. Facilitated diffusion allows drugs to move along their concentration gradient without energy expenditure, while active transport utilizes ATP to drive drug movement against this gradient.
Active transport involves two types of membrane-spanning transporters: uptake and efflux. Uptake transporters are expressed in the small...
Active transport involves two types of membrane-spanning transporters: uptake and efflux. Uptake transporters are expressed in the small...
902
01:23Mechanisms of Drug Absorption: Paracellular, Transcellular, and Vesicular Transport
1.4K
Drugs need to permeate cell membranes to reach their target sites after administration. Orally administered drugs must transcend intestinal epithelial membrane barriers to infiltrate the systemic circulation. Drugs with a molecular weight of less than 500 Daltons diffuse through gaps between neighboring cells, called paracellular pathways.
However, most drugs use the transcellular route, traversing directly through the cell membranes via two mechanisms: passive and active transport. Passive...
However, most drugs use the transcellular route, traversing directly through the cell membranes via two mechanisms: passive and active transport. Passive...
1.4K
01:17Pore Transport and Ion-Pair Transport
1.0K
Pore transport and ion-pair formation are critical mechanisms for the absorption and distribution of drugs in the body.
Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct...
Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct...
1.0K