基于LC-MS/MS 技术对蓝藻Gloeobacter violaceus PCC 7421细胞膜的蛋白质组学研究

Gloeobacter violaceus PCC 7421是一种在进化上很古老的无类囊体蓝藻,由于光合作用电子传递链与呼吸系统在其细胞质膜上共存,这两个系统可能会共享一些元件,为研究其光合作用系统结构的独特之处,应用高效液相色谱-串联质谱联用(LC-MS/MS)技术对其细胞膜蛋白进行蛋白质组学分析.经鉴定发现, G. violaceus的细胞质膜上具有PSⅠ、PSⅡ和细胞色素b6等光合作用关键蛋白,同时具有呼吸作用过程中的关键酶1,5-二磷酸羧化酶/加氧酶、F0F1- ATP酶α和β亚基、细胞分裂蛋白、硝酸盐/亚硝酸盐转运蛋白、青霉素结合蛋白以及多种药物受体ABC转运蛋白.由此可知, G. violaceus的细胞质膜不仅能够同时进行光合作用和呼吸作用,且营养盐运输等转运功能也同时存在.G. violaceus的全基因数据分析显示其基因序列具有独特性,其蛋白注释相对比较少,因此其蛋白功能的研究需要更多数据的支持.

LC-MS/MS analysis of plasmic membrane proteins in Gloeobacter violaceus PCC 7421

Gloeobacter violaceus, which lacks thylakoids, is the earliest branched cyanobacteria in the phylogenetic tree. Photosynthetic and respiratory systems coexist in its plasma membrane. To study of feature of the protein location of photosynthetic and respiration systems, we isolated and used LC-MS/MS to analyze plasma membrane proteins of G. violaceus PCC 7421. The results showed this species had critical photosynthetic reaction center complexes proteins, such as photosystem II protein D1, photosystem I P700 chlorophyll a apoprotein A2, cytochrome b6, and allophycocyanin beta subunit. The ribulose bisophosphate carboxylase was also identified. The ATP synthesis subunits, cell division proteins and nitrate transporters were identified at the same time. Therefore, the plasma membrane not only could carry out photosynthesis and respiration, the nutrient transport and other transport function also existed. Because of the low similarity of its gene with other organisms, many proteins were difficult to be annotated.