The aryl hydrocarbon receptor (AhR) is a very unstable protein. AhR binds to the molecular chaperone complex (HSP90-p23-XAP2) to maintain a stable structure in the cytoplasm. After binding to ligands, such as dioxin, AhR translocates from the cytoplasm to the nucleus with a molecular chaperone complex. The protein forms a heterodimer with Arnt after nuclear transfer, functions as a transcription factor by binding to a xenobiotic responsive element (XRE), and induces the cytochrome P450 1A1 (CYP1A1). Because of the unstable protein, expression of the full-length AhR in the E. coli expression system is very difficult. Many studies investigated AhR using AhR domains in vitro. We expressed and purified the human full-length AhR in E. coli expression system. Furthermore, specific antibodies were prepared. Purified full-length AhR could bind to ligand. In the presence of ligand, α-helix and random coil of AhR increased and β-sheet decreased on CD spectrum. Full-length AhR could bind to HSP90, XAP2 and p23 in the presence or absence of ligand. We now show the biochemical properties of full-length AhR.

中文翻译：

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人全长芳基烃受体（AhR）的生化特性。

芳基烃受体（AhR）是一种非常不稳定的蛋白质。AhR与分子伴侣复合物（HSP90-p23-XAP2）结合以在细胞质中维持稳定的结构。与配体（如二恶英）结合后，AhR与分子伴侣复合物从细胞质转移到细胞核。该蛋白质在核转移后与Arnt形成异源二聚体，通过与异源生物响应元件（XRE）结合而充当转录因子，并诱导细胞色素P450 1A1（CYP1A1）。由于蛋白质不稳定，在大肠杆菌表达系统中全长AhR的表达非常困难。许多研究在体外使用AhR域研究了AhR 。我们在大肠杆菌中表达并纯化了人类全长AhR表达系统。此外，制备了特异性抗体。纯化的全长AhR可以结合配体。在存在配体的情况下，CD光谱上α-螺旋和AhR的无规卷曲增加而β-折叠减少。全长AhR可以在存在或不存在配体的情况下与HSP90，XAP2和p23结合。现在我们显示全长AhR的生化特性。