カスパース-8/p35複合体の結晶構造によって明らかにされた共性阻害
1Department of Biochemistry, Weill Medical College of Cornell University, New York, New York, 10021 USA
Nature
|March 22, 2001
まとめ
バキュロウイルスのp35タンパク質は,カスパスを阻害することによってアポトーシスを防ぐ. 構造的および生化学的研究により,p35が共性結合を形成し,カスパース活性を阻害し,広範囲のプロテアース阻害を提供する新しいメカニズムが明らかになりました.
科学分野:
- 分子生物学は分子生物学である.
- バイオケミストリー バイオケミストリー
- 構造生物学 構造生物学とは
背景:
- アポトーシスは,多細胞生物の発達とホメオスタシスに不可欠な制御されたプロセスです.
- バキュロウイルスのp35タンパク質は,広範囲のカスパース阻害によるアポトーシスの阻害剤として知られています.
研究 の 目的:
- p35媒介のカスパース抑制の分子メカニズムを解明する.
- 人間のカスパース-8.8との複合体でp35の結晶構造を決定する.
主な方法:
- X線結晶学により,p35-caspase-8複合体の3.0 Åの構造を得ました.
- 構造的な発見を検証するための生化学的分析と変異性研究.
主要な成果:
- 構造は,p35とカスパース-8の活性部位との間の共性チオエステル結合を明らかにした.
- クリーバージはp35の形状の変化を誘発し,そのN端を活性部位を遮断するために再配置します.
- p35のN端の変異により,抑制活性が取り消され,その役割が確認されました.
結論:
- p35は,コヴァレンント結合と構造変化を含むカスパース抑制の新しいメカニズムを使用しています.
- p35のN端は,抑制を安定させ,中間水解を防止するために重要である.
- 活性部位外での保存された接触は,p35の広範囲の抑制活性に寄与する.
関連する概念動画
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02:04Covalently Linked Protein Regulators
Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein.
These groups modify specific amino acids in a protein.
02:34Inhibition of CDK Activity
The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...