短乳杆菌DM9218核苷酸代谢过程中的蛋白组学分析

Proteome analysis of Lactobacillus brevis DM9218 in nucleotide metabolism

目的探讨短乳杆菌DM9218在核苷酸代谢过程中的蛋白表达差异。方法分别提取DM9218菌株与底物(肌苷+鸟苷)反应前后的菌体蛋白,利用蛋白双向凝胶电泳(2-DE)技术,找出该菌株与底物反应前后的差异蛋白质点,选取其中差异变化较大的蛋白点进一步做蛋白质谱分析。结果 2-DE分析显示两样品蛋白点主要分布在等电点4~9和分子量11~90 kD范围内,将所得的蛋白点结合其蛋白得率、浓度、储存蛋白含量进行比较,得到匹配的蛋白点数为732个。从中选取14个差异显著的蛋白点进行质谱分析,质谱结果显示所选取蛋白质点主要与物质代谢、能量转换及基因水平转录和翻译等生物学功能密切相关。结论本研究为后期分析研究短乳杆菌DM9218在核苷酸代谢过程中蛋白的表达奠定了基础。

Objective To investigate the ditterential expression ot proteins in the process ot nucleotide metabolism by Lactobacillus brevis DM9218.Methods The total proteins of DM9218 were extracted before（Sample 1） and after（Sample 2） the metabolism of substrates（inosine and guanosin）.Two-dimensional gel electrophoresis（2-DE） was conducted to detect the proteins with significant different expression levels,and the differentially expressed spots were identified by using mass spectrometry assay.Results 2-DE analysis revealed that the protein spots of the two samples mainly distributed in the range of isoelectric point4-9 with molecular weight of 11- 90 kD.By comparing the protein spots as well as the protein yield,concentration and protein level,a total of 732 proteins were matched.From these protein spots,14 ones were identified by using mass spectrometry.The results displayed that the selected proteins were closely related in their biological functions,such as metabolism,energy transformation,gene transcription and translation.Conclusion This research laid the foundation for subsequent analysis on the protein expression of Lactobacillus brevis DM9218 in nucleotide metabolism.