Lu B, McBride B C
Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada.
Oral Microbiol Immunol. 1994 Jun;9(3):166-73. doi: 10.1111/j.1399-302x.1994.tb00054.x.
The heat shock response of Porphyromonas gingivalis was examined by 1- and 2-dimensional polyacrylamide gel electrophoresis after metabolic labeling with [14C]-amino acids. When P. gingivalis cells were shifted from 37 degrees C to 42 degrees C, elevated synthesis of 4 proteins with the apparent molecular weight of 92, 80, 74, and 62 kDa was observed, and synthesis of a 50-kDa protein decreased during heat shock. The 74- and 62-kDa proteins were identified as homologs of Escherichia coli DnaK and GroEL respectively by Western immunoblotting. On 2-dimensional Western blots, 2 forms of DnaK and 4 forms of GroEL were identified due to their slightly different isolelectric points. dnaK and groEL gene homologs were identified in several P. gingivalis strains and some other black-pigmented oral species. DnaK and GroEL homolog proteins were induced when P. gingivalis cells were challenged by ethanol. These proteins were not induced by oxidative stress or change in pH.
在用[14C] -氨基酸进行代谢标记后，通过一维和二维聚丙烯酰胺凝胶电泳检测牙龈卟啉单胞菌的热休克反应。当牙龈卟啉单胞菌细胞从37℃转移至42℃时，观察到明显分子量为92、80、74和62 kDa的4种蛋白质的合成增加，而一种50 kDa蛋白质的合成在热休克期间减少。通过蛋白质免疫印迹法，74 kDa和62 kDa的蛋白质分别被鉴定为大肠杆菌DnaK和GroEL的同源物。在二维蛋白质免疫印迹上，由于其等电点略有不同，鉴定出2种形式的DnaK和4种形式的GroEL。在几种牙龈卟啉单胞菌菌株和一些其他黑色色素沉着口腔菌种中鉴定出了dnaK和groEL基因同源物。当牙龈卟啉单胞菌细胞受到乙醇刺激时，DnaK和GroEL同源蛋白被诱导产生。这些蛋白质不会因氧化应激或pH值变化而被诱导产生。
