関連する実験動画
Updated: Jul 8, 2026
09:47
Analysis of Histone Antibody Specificity with Peptide Microarrays
Published on: August 1, 2017
まとめ
核プロテアゼはヒストンH2Aをカルボキシ末端で割って,新しい断片を作り出します. この特定の割れには高いイオン強度が必要であり,形状に依存する反応を示している.
科学分野:
- バイオケミストリー バイオケミストリー
- 分子生物学は分子生物学である.
- クロマチン生物学 クロマチン生物学
背景:
- ヒストンは,染色体内のDNA包装に不可欠です.
- ヒストンのプロテオリスティックな改変により,クロマチンの構造と機能が変化します.
- ヒストンの改変に関与する特定のタンパク質は,完全に特徴づけられていない.
研究 の 目的:
- 仔牛のチムス染色体に関連したプロテアスを特定し,特徴づけること.
- 特定されたプロテアゼの基板特異性および割れ部位を決定するために.
- タンパク質分解活性に影響する条件を調査する.
主な方法:
- 仔牛の胸腺クロマチンの浄化.
- ヒストンH2Aと関連するプロテアゼの酵素分解.
- アクリルアミドゲル電泳を用いた結果の断片 (cH2A) の分析.
- アミノ酸分析とcH2Aの部分シーケンシング.
- 異なったイオン強度条件下でのプロテアゼ活性の研究.
主要な成果:
- ヒストンH2Aを分断し,断片 (cH2A) を生成するプロテアスが特定されました.
- cH2Aは,H2AのC末端から15個のアミノ酸を除去し,新しいC末端残留物としてバリン114を生成します.
- プロテオリチス活性性は高いイオン強度に依存しており,形状特異的な割れ目を示唆しています.
- プロテアゼは核由来であり,クロマチンと密接に関連しており,解離には1.2MNaClが必要です.
結論:
- クロマチンに関連した新しいH2A特異的な核タンパク質酶が特定されました.
- プロテアゼは,イオン強度によって影響される形状依存の割れ分特異性を示す.
- この酵素は,核内のヒストンの改変に作用する.
関連する概念動画
02:10The Nucleosome Core Particle
Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins.
The paradox
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...
The paradox
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...
02:32Histone Modification
The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitination. Particular combinations of these modifications form “histone codes” that influence the chromatin folding and tissue-specific gene expression.
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
02:25Spreading of Chromatin Modifications
The histone proteins in the nucleosomes are post-translationally modified (PTM) to increase or decrease access to DNA. The commonly observed PTMs are methylation, acetylation, phosphorylation, and ubiquitination of lysine amino acids in the histone H3 tail region. These histone modifications have specific meaning for the cell. Hence, they are called "histone code". The protein complex involved in histone modification is termed as "reader-writer" complex.
Writers
The writer is an enzyme that can...
Writers
The writer is an enzyme that can...
01:01Euchromatin
The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions take up more dye, appearing darker, while the less-compact areas take up less dye and appear lighter. Based on the compaction level, chromatins are classified into two primary forms – euchromatin and heterochromatin.
Euchromatin is the less dense region of the chromatin and stains lighter. Euchromatin contains histone H3 extensively...
Euchromatin is the less dense region of the chromatin and stains lighter. Euchromatin contains histone H3 extensively...
02:38Heterochromatin
The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions that take up more dye are called heterochromatin. Heterochromatin is further classified into two forms – constitutive heterochromatin and facultative heterochromatin.
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th...
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th...
01:12The Nucleosome Core Particle
Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins.
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during...
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during...