空中で伝染する鳥インフルエンザH5のヘマグルーチニンは,原子レベルで見られます
1CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
Science (New York, N.Y.)
|May 4, 2013
まとめ
H5N1インフルエンザのヘマグルチニン (HA) タンパク質の変異により,哺乳類間の空気中感染が可能です. 構造分析は,H5N1が受容体結合を変化させ,鳥の性質を維持し,人間の性質を獲得する方法を示しています.
科学分野:
- ウイルス学 ウイルス学 ウイルス学
- 構造生物学 構造生物学とは
- バイオフィジックス 生物物理学
背景:
- 高致病性のH5N1鳥インフルエンザAウイルスは,パンデミックの脅威となっている.
- ヘマグルチニン (HA) タンパク質の変異は,哺乳類の適応に極めて重要です.
- 哺乳類間のH5N1の空気中感染は大きな懸念事項です.
研究 の 目的:
- H5N1受容体結合の構造的基礎を決定するために.
- H5N1の変異が哺乳類の伝播をどのように促進するかを理解する.
- H5N1.1における受容体結合偏好の変化のメカニズムを解明する.
主な方法:
- 野生型および変異型HAの複雑な構造を決定するためのX線結晶学.
- 鳥類およびヒトの受容体類似体に対する親和性を測定するための拘束力のある測定法.
- 受容体-リガンドの相互作用の生体物理分析.
主要な成果:
- シアリック酸アナログのグリコシド結合におけるシス/トランス形状の変化が観察されました.
- 変異したHAが受容体結合偏好の変化を示すことが示された.
- 変異したHAは,鳥類とヒトの両方の受容体に対する afinities が低いことを発見しました.
結論:
- H5N1の哺乳類への感染への適応に関する構造的および生体学的洞察.
- H5N1はヒトの受容体結合特性を獲得し,鳥類の受容体結合特性を保持することができる.
- これらの適応を理解することは,インフルエンザのパンデミックの予測と制御の鍵です.
さらに関連する動画
08:19Subnanometer-resolution Structural Determination of Hemagglutinin from Cryo-electron Tomography of Influenza Viruses
Published on: November 7, 2025
08:10Production of High-Titer Infectious Influenza Pseudotyped Particles with Envelope Glycoproteins from Highly Pathogenic H5N1 and Avian H7N9 Viruses
Published on: January 15, 2020
関連する概念動画
01:27Influenza
Influenza is an acute, highly communicable viral disease that affects the respiratory tract and is responsible for seasonal epidemics worldwide. Influenza A is the most prevalent type associated with widespread outbreaks and is subtyped based on two surface glycoproteins: hemagglutinin (H) and neuraminidase (N), as in H1N1. These glycoproteins are essential for viral infectivity, transmission, and immune recognition. Transmission occurs primarily through respiratory droplets and contaminated...
02:28Leaky Scanning
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 stands for...
00:36Viral Mutations
A mutation is a change in the sequence of bases of DNA or RNA in a genome. Some mutations occur during replication of the genome due to errors made by the polymerase enzymes that replicate DNA or RNA. Unlike DNA polymerase, RNA polymerase is prone to errors because it is not capable of “proofreading” its work. Viruses with RNA-based genomes, like HIV, therefore accrue mutations faster than viruses with DNA-based genomes. Because mutation and recombination provide the raw material for adaptive...
01:25Hepatitis
Hepatitis is an inflammatory condition of the liver most commonly caused by hepatotropic viruses (A–E), though non-infectious causes such as alcohol and drugs also exist.Hepatitis AHepatitis A virus (HAV) is a non-enveloped RNA virus of the Picornaviridae family. It is primarily transmitted via the fecal-oral route, typically through ingestion of contaminated food or water. After ingestion, HAV enters the bloodstream through the oropharynx or intestinal epithelium and reaches the liver. The...
00:57Viral Recombination
Cells are sometimes infected by more than one virus at once. When two viruses disassemble to expose their genomes for replication in the same cell, similar regions of their genomes can pair together and exchange sequences in a process called recombination. Alternatively, viruses with segmented genomes can swap segments in a process called reassortment.