在线纯化技术应用于MALDI-TOFMS测定溶菌酶的分子量

Application of On-line Purification to Measure The Molecular Weight of Lysozyme by MALDI-TOFMS

在用基质辅助激光解吸电离飞行时间质谱(MALDI-TOFMS)测定蛋白质分子量的过程中,一些盐和蛋白质变性剂经常大大抑制样品信号,产生一些难以解析的离子峰,因此测试前应尽可能去除样品中的添加剂。为此,本研究建立了MALDI—TOFMS测试中在线纯化蛋白质样品的新方法。采用硝酸纤维素膜作为固相载体,将标准蛋白质溶菌酶制成含6 mol/L盐酸胍变性剂、2％SDS表面活性剂的100 mmol/L Tris—HCL溶液进行质谱测定。结果表明:新方法简单、快速,可明显增强离子峰的强度,提高测定蛋白质分子量的灵敏度。

Some salt and denaturants suppress the sample signals in the determination of protein molecular weight by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS), producing the ion peaks that is difficult to be explained, thus the additives in samples should be removed before measurement. A new method for on-line purification of samples with MALDI-TOFMS was established. The standard lysozyme was treated into 100 mmol/L Tris-HCL solution containing 6 mol/L guanidine chloride and 2% SDS surfactant with nitrocellubse membrane as stationary phase. The results showed the method is simple, rapid. Meanwhile, the intensity of signal and the sensitivity were obviously enhanced.