白喉毒素越膜机理研究进展

白喉毒素与细胞膜上的受体结合后,在受体个导的内吞作用下进入胞内体。综述了20世纪90年代后期至今,有关白喉毒素在胞内体的酸性环境中的特性研究。在酸性环境下,白喉毒素发生变构,T区疏水基团暴露并插入膜中,形成粘性孔道。T区形成的粘性孔道与白喉毒素结合,象分子伴侣一样,保持C区的线性结构,并使C区进入细胞膜。由于对白喉毒素作用机理的理解深入,逐渐产生一些新的应用前景。

Recent Development on the Transmembrane Mechanism of Diphtheria Toxin

After bound by the receptor, diphtheria toxin (DT) enter endosomes by receptor mediated endocytosis. This thesis reviewed the recent development on the character of the change of DT in acidic circumstance in endosomes that developed from late 90s'. DT undergoes a conformation changing in acidic solution. The hydrophobic groups in T domain expose and insert into the membrane of endosome than form a sticky channel that can bind the C domain of DT and protect it from improperly folding just like molecular chaperones. The C domain can be translocated into cytoplasm by the T domain without the help of other membrane proteins. Based on the new knowledge obtained recently, some new applications of DT seem possible.