Schlosser Gitta, Pocsfalvi Gabriella, Huszár Emoke, Malorni Antonio, Hudecz Ferenc
Research Group of Peptide Chemistry, Hungarian Academy of Sciences, Eötvös L. University, P. O. Box 32, Budapest 112, Hungary, H-1518.
J Mass Spectrom. 2005 Dec;40(12):1590-4. doi: 10.1002/jms.937.
The effect of matrix composition on signal suppression caused by a dominant compound under MALDI ionization was studied using the combinatorial TQTXT pentapeptide library as a model system. The peptide library is composed of 19 components with all proteinogenic amino acids except cysteine in position X. From these compounds, only the Arg peptide (TQTRT) was detected with sufficient intensity in the MALDI-TOF mass spectrum under typical MALDI conditions (CCA matrix). The analysis of a set of compounds utilized as different matrix components, additives and a cationizing agent revealed that the composition of the matrix is a critical point in signal suppression. Highly improved ion yields were achieved by using a CCA/DHB mixture as a matrix. The addition of K(+) as a cationizing agent to the CCA matrix resulted in MALDI-TOF mass spectra with relative ion intensities very similar to those obtained by electrospray ionization.
使用组合TQTXT五肽文库作为模型系统，研究了基质组成对MALDI电离下由优势化合物引起的信号抑制的影响。该肽文库由19种成分组成，X位置含有除半胱氨酸外的所有蛋白质ogenic氨基酸。在典型的MALDI条件（CCA基质）下，在MALDI-TOF质谱图中，仅能以足够的强度检测到Arg肽（TQTRT）。对用作不同基质成分、添加剂和阳离子化剂的一组化合物的分析表明，基质组成是信号抑制的关键点。通过使用CCA/DHB混合物作为基质，离子产率得到了显著提高。向CCA基质中添加K(+)作为阳离子化剂，得到的MALDI-TOF质谱图的相对离子强度与通过电喷雾电离获得的非常相似。
