基质辅助激光解吸电离飞行时间质谱检测蛋白质分子量的优化研究

摘要

[目的]研究采用基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)技术检测蛋白质分子量的优化条件.[方法]选择3种不同的基质检测牛血清白蛋白(BSA)的分子量,在选定最佳基质化合物的基础上,通过改变样品蛋白质的浓度,以获得高质量的质谱峰图,确定蛋白质样品的最小和最优检测量.[结果]1 μg蛋白质样品与10 mg/mL含0.1％乙酸(TFA)和50％乙腈(ACN)的芥子酸(SA)基质水溶液混合检测分子量,可产生最高质量的MALDI-TOF-MS峰图,同时蛋白质样品最小检测量应不少于500 ng.[结论]MALDI-TOF-MS技术操作简单、分析快速、灵敏度高,是一种检测蛋白质分子量的可靠方法；研究结果确定了获得最优化质谱峰的最佳组合,这是从高度复杂的蛋白质样品测定准确分子量的必备条件.%[Objective]The optimum conditions for measuring protein molecular weight were studied using matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS).[Method]Three different matrices,viz.,sinapic acid (SA),α-cyano-4-hydroxycinnamic acid (CHCA) and 2,5-dihydroxybenzoic acid (DHB) were tested for determination of molecular weight of bovine serum albumin (BSA) and the effects of different sample concentration were observed on quantification of protein samples.[Result] The results demonstrated that 1 μg protein samples and sinapic acid (SA)matrix dissolved in water solvent (containing 0.1% trifluoroacetic acid and 50% acetonitrile to generate the concentration of 10 mg/mL) produced the best quality of MALDI-TOF-MS spectra.The sample required to determine the exact quantity was optimized as 500 ng.[Conclusion]This technique is convenient,rapid,sensitive and reliable for determining protein molecular weight.The optimal combination was determined to obtain optimum mass spectra,necessary for obtaining accurate molecular weight of highly complicated protein samples.