TOP1 蛋白, Human (575a.a, sf9, His)

The TOP1 protein is critical in cellular processes, mitigating DNA supercoiling and torsional tension during replication and transcription. It does this by transiently cutting and rejoining a DNA strand, introducing breaks through transesterification. TOP1 Protein, Human (575a.a, sf9, His) is the recombinant human-derived TOP1 protein, expressed by Sf9 insect cells , with N-His labeled tag. The total length of TOP1 Protein, Human (575a.a, sf9, His) is 575 a.a., with molecular weight of ~70.4 kDa.

TOP1 蛋白通过减轻 DNA 复制和转录过程中产生的 DNA 超螺旋和扭转张力，在细胞过程中发挥关键作用。这是通过 DNA 双链体一条链的瞬时切割和随后的重新连接来实现的。该酶通过酯交换作用在双链 DNA 的特定靶位点引入单链断裂，从而形成 DNA-(3'-磷酸酪氨酰)-酶中间体。该中间体排出 5'-OH DNA 链，使游离 DNA 链围绕相反链上完整的磷酸二酯键旋转，从而有效去除 DNA 超螺旋。在最后的再连接步骤中，DNA 5'-OH 攻击共价中间体，导致活性位点酪氨酸被驱逐并恢复 DNA 磷酸二酯主链。除了在 DNA 拓扑维持中的作用之外，TOP1 还参与选择性剪接的调节，其对内皮细胞中组织因子 (F3) 前 mRNA 的影响就是例证。此外，它通过修改 BMAL1 启动子上 ROR 响应元件 (RORE) 周围的染色质结构，有助于核心生物钟组件 BMAL1 的昼夜节律转录。

Human

Sf9 insect cells

N-His

P11387 (K191-F765)

7150  [NCBI]

Approximately 70.4 kDa

Greater than 90% as determined by reducing SDS-PAGE.

溶液.

Supplied as a 0.2 μm filtered solution of 20 mM Tris, 200 mM NaCl, 20 % glycerol, pH 7.5.

<1 EU/μg, determined by LAL method.

N/A.

Stored at -80°C for 1 year. It is stable at -20°C for 3 months after opening. It is recommended to freeze aliquots at -80°C for extended storage. Avoid repeated freeze-thaw cycles.

Shipping with dry ice.