【摘要】 目的:探索影响金黄色葡萄球菌肠毒素C2(SEC2)断裂的因素。方法:将纯化的肠毒素在不同条件下处理,观察环境因素对其断裂程度的影响。结果:重组SEC2断裂的位置可能位于其分子93位半胱氨酸与110位半胱氨酸之间。重组SEC2在37℃下、24 h内会完全产生断裂,在碱性条件下则加速其断裂的形成;H2O2会导致重组SEC2产生非特异性降解。当溶液中有β-巯基乙醇(2%)、苯甲基磺酰胺(5~10 mmol/L)、咪唑(1 mol/L)或大肠杆菌粗提物时,重组SEC2的断裂可被有效抑制。结论:肠毒素C2容易在特定位点发生断裂,可能与蛋白质本身结构有关。更多还原

【Abstract】 Objective: To investigate the limited digestion of recombinant staphylococcal enterotoxin C2(SEC2-His) in different conditions.Methods: The purified recombinant SEC2-His was treated with different reagents and the cleavage of rSEC2 molecule was observed by SDSPAGE.Results: The cleavage occurred in positions Cys93-Cys110 of the disulfide loop.Complete auto-cleavage of recombinant SEC2 was observed in solution at 37℃ within 24 hrs,and that was accelerated under alkaline conditions.The auto-cleavage of the recombinant protein was inhibited in the presence of β-ME(2%),PMSF(5-10 mmol/L),imidazole(1 mol/L) or crude E.coli lysate.Non-specific degradation of recombinant SEC2 was promoted with the increasing of the concentration of H2O2.Conclusion: The recombinant SEC2-His is broken down in special site of protein,which may be associated with the protein structure.更多还原