[Object]We investigated the proteomic profile of Lactobacillus brevis NCL912 under optimum pH and acidic pH in the media without the addition of sodium L- glutamate to characterize the differential expression proteins and function by two-dimensional gel electrophoresis.[Methods]The differential expression proteins were separated and analyzed by two-dimensional gel electrophoresis, mass spectrum and bioinformatics.[Results]The results showed that the two-dimensional gel electrophoresis profiles of L.brevis NCL912 were uniformity, well-resolution and repeatability.25 proteins were differently expressed in the two profiles.Among them, 8 proteins were identified and analyzed by the mass spectrum and bioinformatics due to the lack of genome sequence data of L.brevis NCL912.These proteins played the roles of the synthesis of protein and DNA, glycolysis and regulating the cellular energy level.[Conclusion]The differential expression proteins might play the important role in the acid stress resistance mechanism which may protect cell against acid stress.%[目的]本文从蛋白质组水平,对本实验室分离的一株高产γ-氨基丁酸的短乳杆菌NCL912(Lactobacillus brevis)在酸胁迫下蛋白质的差异表达及其应激机理进行探讨.[方法]利用双向凝胶电泳技术对pH 5.0和pH 4.0条件下,不含L-谷氨酸钠的培养物的蛋白质组电泳图谱进行了分析,并对酸胁迫下差异表达的蛋白进行了比较.利用质谱检测技术和生物信息学技术对这些差异表达的蛋白进行了鉴定、功能分类和代谢途径分析等.[结果]通过双向凝胶电泳技术,可以得到均匀、背景清晰、分辨率高、重复性好的Lb.brevis NCL912的双向凝胶电泳图谱.对pH 5.0和pH 4.0条件下培养的该菌总蛋白质电泳图谱进行比较,发现有25个差异表达的蛋白点.对这25个差异表达的蛋白进行了质谱鉴定.由于缺乏短乳杆菌NCL912的全基因组,所以其中只有8个蛋白点被质谱鉴定和分析得到.它们分别参与了蛋白质的合成、核苷酸的合成、糖酵解代谢、细胞能量水平的调节等.[结论]酸应激下这些表达蛋白质可通过其相应的功能来保护细胞耐受酸胁迫,从而使菌能够在酸性环境下生存增值.这可能就是Lb.brevis NCL912的酸胁迫应激机理之一.
展开▼
