Deng Kaiping, Hansen Eric J
Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9048, USA.
Infect Immun. 2003 Nov;71(11):6633-40. doi: 10.1128/IAI.71.11.6633-6640.2003.
The cytolethal distending toxin (CDT) of Haemophilus ducreyi is comprised of the CdtA, CdtB, and CdtC proteins, with the CdtB protein having demonstrated enzymatic (i.e., DNase) activity. Using a single recombinant Escherichia coli strain with two plasmids individually containing the H. ducreyi cdtA and cdtC genes, we purified a noncovalent CdtA-CdtC complex. Incubation of this CdtA-CdtC complex with HeLa cells blocked killing of these cells by CDT holotoxin. Furthermore, the addition of purified recombinant CdtB to HeLa cells preincubated with the CdtA-CdtC complex resulted in the killing of these human epithelial cells.
杜克雷嗜血杆菌的细胞致死性膨胀毒素(CDT)由CdtA、CdtB和CdtC蛋白组成,其中CdtB蛋白已显示出酶活性(即脱氧核糖核酸酶活性)。我们使用单个重组大肠杆菌菌株,该菌株带有两个分别含有杜克雷嗜血杆菌cdtA和cdtC基因的质粒,纯化了一种非共价的CdtA-CdtC复合物。将这种CdtA-CdtC复合物与HeLa细胞一起孵育可阻止这些细胞被CDT全毒素杀死。此外,将纯化的重组CdtB添加到预先与CdtA-CdtC复合物孵育的HeLa细胞中,会导致这些人上皮细胞死亡。