Programmed cell death (apoptosis) is an essential mechanism in life that tightly regulates embryogenesis and removal of harmful cells. Besides an extrinsic pathway, an intrinsic (mitochondrial) apoptotic pathway exists where mitochondria are actively involved in cellular clearance in response to internal stress signals. Pro-apoptotic (death) and anti-apoptotic (survival) members of the B cell CLL/lymphoma-2 (Bcl-2) protein family meet at the mitochondrion's surface where they accurately regulate apoptosis. Overexpression of the anti-apoptotic Bcl-2 protein is a hallmark for many types of cancers and in particular for many treatment resistant tumors. Bcl-2 is a membrane protein residing in the mitochondrial outer membrane. Due to its typical membrane protein features including very limited solubility, it is difficult to express and to purify. Therefore, most biophysical and structural studies have used truncated, soluble versions. However, to understand its membrane-coupled function and structure, access to sufficient amount of full-length human Bcl-2 protein is a necessity. Here, we present a novel, E. coli based approach for expression and purification of preparative amounts of the full-length human isoform 2 of Bcl-2 (Bcl-2(2)), solubilized in detergent micelles, which allows for easy exchange of the detergent.

中文翻译：

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全长抗凋亡膜蛋白Bcl-2的新型重组表达和纯化方法。

程序性细胞死亡（细胞凋亡）是生命中至关重要的机制，它可以严格调节胚胎发生和有害细胞的去除。除了外部途径外，还存在内在（线粒体）凋亡途径，其中线粒体响应内部压力信号而积极参与细胞清除。B细胞CLL /淋巴瘤2（Bcl-2）蛋白家族的促凋亡（死亡）成员和抗凋亡（生存）成员在线粒体表面相遇，在那里它们精确地调节细胞凋亡。抗凋亡的Bcl-2蛋白的过表达是许多类型癌症的标志，尤其是对于许多具有治疗抗性的肿瘤。Bcl-2是存在于线粒体外膜中的膜蛋白。由于其典型的膜蛋白特性（包括非常有限的溶解度），很难表达和纯化。因此，大多数生物物理和结构研究都使用了截短的可溶形式。但是，要了解其膜偶联功能和结构，必须获得足够量的全长人Bcl-2蛋白。在这里，我们提出了一种新型的基于大肠杆菌的方法，用于表达和纯化制备型量的Bcl-2（Bcl-2（2））全长人同工型2，可溶于洗涤剂胶束中，从而易于交换洗涤剂。