Video Experimental Relacionado
Updated: Jun 26, 2026
11:55
Membrane Transport Processes Analyzed by a Highly Parallel Nanopore Chip System at Single Protein Resolution
Published on: August 16, 2016
El paso transmembranar de compuestos hidrofóbicos a través de la pared de un canal proteico
Elizabeth M Hearn1, Dimki R Patel, Bryan W Lepore
1Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA.
Nature
|February 3, 2009
Resumen
El estudio revela el primer mecanismo de difusión lateral para la absorción de compuestos hidrofóbicos por el transportador de ácidos grasos de cadena larga (FadL) de Escherichia coli. Este hallazgo tiene implicaciones para la comprensión de las infecciones bacterianas y la biorremediación ambiental.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Biología Molecular Biología Molecular
- Biología Estructural Biología estructural.
Sus antecedentes:
- Las proteínas de membrana que transportan compuestos hidrofóbicos son cruciales para la resistencia a múltiples fármacos y las enfermedades.
- El transporte de sustratos hidrofóbicos a través de canales acuosos es energéticamente desfavorable.
- La difusión lateral de las bicapas lipídicas es un mecanismo propuesto para el transporte hidrofóbico de sustratos.
Objetivo del estudio:
- Para investigar el mecanismo de transporte del transportador de ácidos grasos de cadena larga (FadL) de la membrana externa de Escherichia coli.
- Para presentar el primer ejemplo de un mecanismo de difusión lateral para la absorción hidrofóbica de sustratos.
Principales métodos:
- Análisis estructural de las FadL de Pseudomonas aeruginosa.
- Caracterización de un mutante FadL con una abertura lateral estrecha.
Principales resultados:
- Un mutante de FadL con una abertura lateral estrecha mostró una alteración en el transporte del sustrato.
- La estructura cristalina reveló una abertura lateral conservada y un túnel hidrofóbico en FadL.
- Este túnel probablemente media el paso del sustrato desde el exterior hacia la bicapa lipídica.
Conclusiones:
- FadL utiliza un mecanismo de difusión lateral para la absorción hidrofóbica del sustrato.
- Este mecanismo implica un túnel hidrofóbico y una abertura lateral en la pared del cañón.
- Los homólogos de FadL en bacterias patógenas y ambientales sugieren implicaciones para el control de infecciones y la biorremediación.
Videos de Conceptos Relacionados
01:25Single-pass Transmembrane Proteins
Integral membrane proteins are tightly associated with the cell membrane and play a crucial role in cell communication, signaling, adhesion, and transport of the molecules. Some integral membrane proteins are present only in the membrane monolayer. For example, the enzyme fatty acid amide hydrolase is present in the cytoplasmic side of the membrane monolayer. In contrast, another type of integral membrane protein, also known as a transmembrane protein, spans across the membrane. Transmembrane...
01:09Multi-pass Transmembrane Proteins and β-barrels
In multi-pass transmembrane proteins, the polypeptide chain crosses the membrane more than once. The transmembrane polypeptide chain either forms an α-helix or β-strand structure. α-Helix containing multi-pass transmembrane proteins are ubiquitous, whereas β-strand containing ones are mainly found in gram-negative bacteria, mitochondria, and chloroplasts.
α-Helix containing multi-pass transmembrane proteins
Multi-pass transmembrane proteins such as G-protein-linked receptors (GPCRs) and...
α-Helix containing multi-pass transmembrane proteins
Multi-pass transmembrane proteins such as G-protein-linked receptors (GPCRs) and...
01:44The Significance of Membrane Transport
The transport of solutes across the cell membrane is essential for metabolic processes, like maintaining cell size and volume, generating the action potential, exchanging nutrients and gases, etc. Membrane transport can be either passive or active. It can be simple diffusion, facilitated, or mediated transport aided by transport proteins such as transporters and channels.
Transporters facilitate either an active or passive movement of solutes. They can allow a single-molecule transport down its...
Transporters facilitate either an active or passive movement of solutes. They can allow a single-molecule transport down its...
01:26Insertion of Single-pass Transmembrane Proteins in the RER
Integral membrane proteins are proteins adhered to the lipid bilayer of a cell organelle or membrane. They can be of two types: transmembrane integral proteins that span the lipid bilayer and monotopic proteins that are attached to either side of the membrane but do not pass through it.
Integral transmembrane proteins possess transmembrane and extra membrane domains. The transmembrane domains are primarily made of 20-25 hydrophobic amino acids arranged in a helical secondary confirmation. These...
Integral transmembrane proteins possess transmembrane and extra membrane domains. The transmembrane domains are primarily made of 20-25 hydrophobic amino acids arranged in a helical secondary confirmation. These...
01:29Insertion of Multi-pass Transmembrane Proteins in the RER
The rough ER membrane synthesizes, assembles, and embeds transmembrane proteins in diverse topologies. These proteins function as transporters or channels and can remain in the ER membrane or are sent to the Golgi complex, lysosome, and cell membrane.
The multipass transmembrane proteins are the type IV integral membrane proteins with multiple topogenic sequences determining their spatial arrangement in the ER membrane. Nearly all multipass proteins lack a cleavable signal sequence and use...
The multipass transmembrane proteins are the type IV integral membrane proteins with multiple topogenic sequences determining their spatial arrangement in the ER membrane. Nearly all multipass proteins lack a cleavable signal sequence and use...
01:25Aquaporins
Aquaporins or AQPs are a family of integral membrane proteins whose primary function is to transport water, while some called aquaglyceroporins also transport glycerol. In addition, aquaporins have also been suspected to be involved in transporting volatile substances, such as carbon dioxide and ammonia, across membranes. Such AQPs that act as gas channels are often highly expressed in cells involved in the gaseous exchange, such as red blood cells, epithelial cells, and pulmonary capillaries.