Video Experimental Relacionado
Updated: Oct 6, 2025
07:56
User-friendly, High-throughput, and Fully Automated Data Acquisition Software for Single-particle Cryo-electron Microscopy
Published on: July 29, 2021
3.7K
Variante Omicron del SARS-CoV-2: Evasión de anticuerpos y estructura criogénica del complejo de la proteína del
Dhiraj Mannar1, James W Saville1, Xing Zhu1
1Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada.
Science (New York, N.Y.)
|January 20, 2022
Resumen
La variante Omicron
Área de la Ciencia:
- Virología
- Biología estructural
- Inmunología
Sus antecedentes:
- La variante Omicron del SARS-CoV-2 está emergiendo como la cepa mundial dominante.
- Comprender las adaptaciones moleculares de Omicron es crucial para las estrategias de salud pública.
Objetivo del estudio:
- Para aclarar la base estructural y bioquímica para el aumento de la transmisibilidad de Omicron.
- Investigar la interacción de Omicron con el receptor ACE2 humano y sus propiedades de evasión de anticuerpos.
Principales métodos:
- Microscopía criolectrónica (Cryo-EM) para el análisis estructural del complejo de proteína de punta Omicron-ACE2.
- Ensayos bioquímicos para determinar las afinidades de unión al ACE2.
- Pruebas de neutralización con pseudovirus para evaluar la evasión de anticuerpos.
Principales resultados:
- La proteína del pico Omicron forma nuevas interacciones (puentes de sal, enlaces de hidrógeno) con ACE2 a través de los residuos mutados R493, S496 y R498.
- Estas interacciones compensan las mutaciones que reducen la afinidad de unión, manteniendo una unión similar de ACE2 a Delta.
- La proteína del pico Omicron exhibe una mayor evasión de anticuerpos en comparación con las variantes anteriores.
Conclusiones:
- La combinación de retención de la unión ACE2 y el aumento de la evasión de anticuerpos contribuye a la rápida propagación de Omicron.
- Los conocimientos estructurales sobre las características moleculares de Omicron son clave para comprender su potencial pandémico.
Videos de Conceptos Relacionados
01:28Cryo-electron Microscopy
3.7K
Conventional electron microscopy (EM) involves dehydration, fixation, and staining of biological samples, which distorts the native state of biological molecules and results in several artifacts. Also, the high-energy electron beam damages the sample and makes it difficult to obtain high-resolution images. These issues can be addressed using cryo-EM, which uses frozen samples and gentler electron beams. The technique was developed by Jacques Dubochet, Joachim Frank, and Richard Henderson, for...
3.7K
00:56Viral Structure
66.0K
Viruses are extraordinarily diverse in shape and size, but they all have several structural features in common. All viruses have a core that contains a DNA- or RNA-based genome. The core is surrounded by a protective coat of proteins called the capsid. The capsid is composed of subunits called capsomeres. The capsid and genome-containing core are together known as the nucleocapsid.
66.0K
02:50Conjugated Proteins
19.3K
Simple proteins and protein complexes contain only amino acids. In contrast, many other proteins, called conjugated proteins, covalently bond with non-protein moieties.
Nucleoproteins are protein complexes that contain nucleic acids, categorized as deoxyribonucleoproteins (DNPs) or ribonucleoproteins (RNPs) respectively. The nucleosome is a typical example of a DNP where nuclear DNA is associated with histone proteins. The major antigen for the Covid-19 virus SARS-CoV is an RNP that is critical...
Nucleoproteins are protein complexes that contain nucleic acids, categorized as deoxyribonucleoproteins (DNPs) or ribonucleoproteins (RNPs) respectively. The nucleosome is a typical example of a DNP where nuclear DNA is associated with histone proteins. The major antigen for the Covid-19 virus SARS-CoV is an RNP that is critical...
19.3K
01:26Antibody Actions
1.5K
Antibodies, or immunoglobulins, are critical players in the immune system's arsenal against invading pathogens. Produced by B cells and plasma cells, their primary role is to detect and bind to specific antigens, molecules found on the surface of pathogens like bacteria or viruses. Beyond antigen recognition, antibodies perform several vital functions that contribute to immune defense.
Neutralization
Antibodies can bind to pathogens, preventing them from infecting host cells. This process...
Neutralization
Antibodies can bind to pathogens, preventing them from infecting host cells. This process...
1.5K
02:28Leaky Scanning
5.3K
During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R...
5.3K