Matrix performance in matrix-assisted laser desorption/ionization for molecular weight determination in sialyl and non-sialyl oligosaccharide proteins.
Matrix performance in matrix-assisted laser desorption/ionization for molecular weight determination in sialyl and non-sialyl oligosaccharide proteins.
复制标题
用于唾液酸和非唾液酸寡糖蛋白分子量测定的基质辅助激光解吸/电离中的基质性能。
DOI：
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发表时间：
1997
影响因子：
2
通讯作者：
C. Minoia
中科院分区：
文献类型：
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作者：
C. Sottani;M. Fiorentino;C. Minoia
基质辅助激光解吸/电离(MALDI)质谱仪依靠完整分子离子的形成来确定分子量。在生化研究中，传统的蛋白质分析方法，如十二烷基硫酸钠-聚丙烯酰胺凝胶电泳法，已被这种新的电离方法所取代。不幸的是，由质量精度和低分辨率引起的问题限制了这种电离技术的使用，特别是当要求在高质量范围内具有高质量精度时。本文指出，适当选择决定糖蛋白解吸/电离的参数，可以提高MALDI质谱图的质量，提高质量重复性和分辨率。通过对样品基质溶液组成、pH和仪器条件的研究，可以测定含高百分比唾液酸的高糖化蛋白质的分子量，例如促红细胞生成素。该分子的糖基化干扰了电喷雾电离中多电荷离子的产生，但不影响MALDI分析中的解吸/电离。我们报告了用来确定促红细胞生成素异质性程度的最佳操作条件。
Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry relies on the formation of intact molecular ions to determine molecular weight. In biochemical research, conventional methods of protein analysis at picomol to fentomol sensitivity, such as sodium dodecyl sulphate polyacrylamide gel electrophoresis, have been replaced by this new ionization method. Unfortunately, problems caused by the mass accuracy and low resolution restrict the use of this ionization technique, particularly when a high mass accuracy in a high mass range is required. In this paper it is shown that the appropriate choice of parameters which determine the desorption/ionization of glycoproteins can improve the quality of MALDI mass spectra as well as mass reproducibility and resolution. The study of sample-matrix solution composition, pH and instrumental conditions allow the molecular weight determination of highly glycosylated proteins with a high percentage of sialic acid, e.g. erythropoietin. The glycosylation of this molecule which interferes with the production of multiply charged ions in electrospray ionization does not affect the desorption/ionization in MALDI analysis. We report the best operating conditions used to establish the degree of heterogeneity of erythropoietin.