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旨在用蛋白质组学方法揭示枯草芽胞杆菌Bacillus subtilis 168将顺丙烯磷酸转化成磷霉素的机理。B.subtilis 168能够将顺丙烯磷酸不对称转化成磷霉素。气相色谱分析发现在转化培养基发酵液中的磷霉素的含量达816.6μg/mL,转化率为36.05%。将分别培养在含有底物和不含底物的培养基中的B.subtilis 168的胞质蛋白进行双向凝胶电泳。对两种条件下的电泳图谱进行比较,发现有98个差异表达蛋白。其中在有底物存在时,表达量下调的点有20个,表达量上调的点52个,底物特异性表达的点有26个。对差异表达蛋白进行质谱鉴定,共鉴定到80个蛋白点,其中下调的点17个,上调的点45个,底物特异性表达的点18个。这些蛋白分别参与胁迫反应、氧化还原反应、物质转运、核苷酸代谢、糖代谢、氨基酸和蛋白质代谢等。根据上述对B.subtilis 168蛋白质组学分析结果,推测菌株是通过两步将顺丙烯磷酸转化成磷霉素的。第一步是水化反应,第二步是脱氢反应。
Aim To proteomically reveal the mechanism by which B. subtilis Bacillus subtilis 168 converts cis-propylene phosphate to fosfomycin. B. subtilis 168 is capable of converting asymmetric cis-phosphityl acid to fosfomycin. Gas chromatography analysis found that the content of fosfomycin in the fermentation broth of the transformation medium reached 816.6μg / mL with a conversion rate of 36.05%. The cytoplasmic proteins of B. subtilis 168 cultured in medium with and without substrate were separately subjected to two-dimensional gel electrophoresis. Electrophoretic patterns were compared between the two conditions and 98 differentially expressed proteins were found. In the presence of substrate, there were 20 down-regulated spots, 52 up-regulated spots, and 26 specific substrate-specific spots. A total of 80 protein spots were identified, including 17 down-regulated spots, 45 up-regulated spots and 18 specific spots. These proteins are involved in stress response, redox reaction, substance transport, nucleotide metabolism, glucose metabolism, amino acid and protein metabolism. Based on the above-described proteomic analysis of B.subtilis 168, it was presumed that the strain transformed the maleic acid into fosfomycin in two steps. The first step is the hydration reaction and the second step is the dehydrogenation reaction.