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

Optimization of conditions for determination of protein molecular weight using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

  • 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.

     

    Abstract: The optimum conditions for measuring protein molecular weight were studied using matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS).MethodThree 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.ConclusionThis 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.

     

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