Fitzgerald M C, Parr G R, Smith L M
Department of Chemistry, University of Wisconsin, Madison 53706.
Anal Chem. 1993 Nov 15;65(22):3204-11. doi: 10.1021/ac00070a007.
In order to examine the importance of pH in the matrix-assisted laser desorption/ionization (MALDI) analysis of proteins and oligonucleotides, 37 highly substituted pyrimidine, pyridine, and benzene derivatives containing basic amino groups were screened as potential matrices. Several of these compounds were useful for the preparation and analysis of samples under neutral and basic pH conditions. The matrix, 2-amino-4-methyl-5-nitropyridine, gave good results with small proteins (up to approximately 12,000 Da). The best results with oligonucleotides were obtained with 2-amino-5-nitropyridine, which was a useful matrix for the analysis of mixed-base oligonucleotides smaller than 20 nucleotides in length and homopolymers of thymidine. In general, oligonucleotide analysis using basic matrices was found to be subject to similar constraints of size and base composition that hold when acidic matrices are used. A major advantage of these newly discovered matrix materials over the more commonly used acidic matrices is that they extend the utility of MALDI to the analysis of acid-sensitive species.
为了研究pH值在蛋白质和寡核苷酸基质辅助激光解吸/电离（MALDI）分析中的重要性，筛选了37种含有碱性氨基的高度取代嘧啶、吡啶和苯衍生物作为潜在基质。其中几种化合物可用于在中性和碱性pH条件下制备和分析样品。基质2-氨基-4-甲基-5-硝基吡啶对小蛋白质（分子量高达约12,000 Da）效果良好。寡核苷酸分析的最佳结果是使用2-氨基-5-硝基吡啶获得的，它是分析长度小于20个核苷酸的混合碱基寡核苷酸和胸苷同聚物的有用基质。一般来说，发现使用碱性基质进行寡核苷酸分析受到与使用酸性基质时类似的大小和碱基组成限制。这些新发现的基质材料相对于更常用的酸性基质的一个主要优点是，它们将MALDI的应用扩展到了对酸敏感物种的分析。
