MATRIX ASSISTED LASER DESORPTION--FUNDAMENTAL STUDIES

基质辅助激光解吸(MALD)与飞行时间质量耦合 近年来，光谱分析已成为一种强大的资源 生物医学研究员。应用于分析范围广泛的 生物分子的重要类别，包括蛋白质、多肽、 单抗、寡核苷酸和糖肽以及 糖蛋白尤其令人印象深刻。科学发展观的基础研究 基质辅助激光解吸的基本机理是 需要更好地了解解吸过程 它本身。这类研究可望扩大 技术，并在分子质量等领域提供改进 准确度、灵敏度和质量分辨率。 主要关注的是基质/分析物相互作用的性质。为 观察到了多肽和蛋白质、重要的基质加合物种类。 这些物种形成的确切机制尚不清楚，但 包括简单的脱水和脱羧基反应。最终结果是 是干扰准确测定a的离子物种 样品的相对分子质量，特别是对大质量分析物，如 蛋白质。旨在阐明这些疾病的性质的各种研究 描述了基质加合物种类，目的是减少或 消除了这些麻烦的反应，从而提高了 从这项技术中获得的数据。事实上，如果这能实现的话 完成后，很可能更复杂的生物分子 可以用这种技术探测系统。示例包括绑定 从各种小分子(如药物)到大分子的研究 蛋白质(超过30,000 Da)，目前很难执行 用这种技术。 提出了提高MALD性能的仪器方法 技术。这些措施包括利用来自 传统的双扇区质谱计作为能量过滤器 提高可用的质量分辨率。这将允许更多 对基质加合反应进行了详细的研究，并改进了 生物分子研究的实用工具。为了增加结构 从MALD实验中获得的信息，表面诱导 描述了用于进行MS/MS实验的解离研究 MALD产生的质子化分子离子。

Matrix assisted laser desorption (MALD) coupled to time-of-flight mass spectrometry has emerged in recent years as a powerful resource for the biomedical researcher. Applications to the analysis of a wide range of important classes of biomolecules, including proteins, peptides, monoclonal antibodies, oligonucleotides and glycopeptides and glycoproteins have been particularly impressive. Basic studies of the fundamental mechanism involved in matrix assisted laser desorption are needed to gain an improved understanding of the desorption process itself. Such studies are expected to expand the applicability of the technique and provide improvements in such areas as molecular mass accuracy, sensitivity and mass resolution. A primary concern is the nature of the matrix/analyte interactions. For peptides and proteins, significant matrix adduct species are observed. The exact mechanism for formation of these species is not known, but involve simple dehydration and decarboxylation reactions. The net result are ion species which interfere with the accurate determination of a samples molecular weight, particularly for large mass analytes such as proteins. A variety of studies aimed at elucidating the nature of these matrix adduct species are described, with the goal of reducing or eliminating these troublesome reactions, thus improving the utility of the data available from this technique. Indeed, if this can be accomplished, it is probable that even more complicated biomolecular systems can be probed by this technique. Examples include binding studies of various small molecules (such as pharmaceuticals) to large proteins (more than 30,000 Da), which currently are difficult to perform with this technique. Instrumental methods are proposed to improve the performance of the MALD technique. These include utilizing an electrostatic sector from a conventional double sector mass spectrometer as an energy filter to improve the mass resolving power available. This will allow more detailed studies of the matrix adduct reactions as well as improving the utility for biomolecular studies. In order to increase the structural information available from the MALD experiment, surface induced dissociation studies are described for performing MS/MS experiments on the protonated molecular ions produced by MALD.