驱除侵袭大质粒pINV对福氏2a志贺氏杆菌2457T影响的比较蛋白质组学研究

将福氏志贺氏杆菌2a 2457T及其驱除侵袭大质粒pINV的菌株培养至对数生长中期，制备了全细胞蛋白质。用双向电泳分离两种细胞蛋白质混合物并进行比较，找出差异点，这些点经过胶内酶切后进行MALDI_TOF质谱鉴定。每个蛋白质点的肽指纹图谱都在福氏志贺氏杆菌2a 2457T株的蛋白质数据库用Mascot进行检索，共发现了10个差异表达的蛋白质。结果显示驱除大质粒后几个参与核酸代谢途径的酶表达量有所上升。其中胞啶/脱氧胞啶脱氨酶、嘌呤核苷磷酸化酶和尿嘧啶核苷磷酸化酶表达量的上升可能造成尿嘧啶和尿（嘧啶核）苷合成的增加。

Comparative proteomics research on removing of large invasive plasmid pINV of Shigella flexneri 2a strain 2457T

S. flexneri 2a strain 2457T and its derivative without large invasive plasmid pINV_2457T were cultured to middle logarithm phase. Whole cellular protein extracts of the two strains were examined by two dimensional(2D) electrophoresis using immobilized pH gradient(IPG) technology. After in_gel protein digestion, the different_expressed spots were detected by matrix_assisted laser desorption ionization_time of flight mass spectrometry (MALDI TOF MS). All the peptide mass fingerprints (PMFs) were searched by the program Mascot developed by Matrix Science Ltd. For identifying proteins, databases ofS. flexneri2a 2457T was used. Ten proteins with changed expression level were found. Results indicate that expression levels of several enzymes involved in nucleic acid metabolism have risen, and expression increase of deoxycytidine deaminase, purine nucleoside phosphorylase, and uridine nucleoside phosphorylase might lead to increase of uridine and uridine nucleoside synthesization.