Analysis of the interaction of Clostridium perfringens enterotoxin with claudin

产气荚膜梭菌肠毒素（Clostridium perfringens enterotoxin， CPE）是一种成孔毒素，是引起食物中毒的病原体。Claudin是一种紧密连接的组成部分，是一种四跨膜蛋白，它构成了一个大家庭，有20多个成员，并不是所有的成员都作为CPE的受体。这种毒素区分敏感克劳丁的机制尚不清楚。在这项研究中，我们将claudin负责与CPE相互作用的区域定位在第二个细胞外环的c端12个氨基酸上，并发现碱性claudin区域和酸性CPE间隙之间的静电吸引参与了它们的相互作用。此外，我们给出了在2.0 Å用x射线晶体学测定的CPE结构。这些结构特征表明CPE是一种β成孔毒素。

Clostridium perfringens enterotoxin (CPE), a causative agent of food poisoning, is a pore-forming toxin. Claudin, a component of tight junctions, is a tetratransmembrane protein and constitutes a large family of more than 20 members, not all of which serve as the receptor for CPE. The mechanism by which the toxin distinguishes the sensitive claudins is unknown. In this study, we localized the region of claudin responsible for interaction with CPE to the C-terminal 12 amino acids of the second extracellular loop and found that an electrostatic attraction between the basic claudin region and the acidic CPE cleft is involved in their interaction. Furthermore, we present the structure of CPE determined by X-ray crystallography at 2.0 Å. These structural features imply that CPE is a β pore-forming toxin.