Negative Ion Mass Spectrometry in Peptide Sequencing

将开发一种新的多肽测序方法，包括负离子质谱学。负化学电离质谱仪(NCI-MS)可以显著提高灵敏度，以跟上自动化蛋白质测序的机械和工程改进的步伐。据报道，对于电子捕获能力很强的分子，NCI-MS的检测下限在飞摩尔到阿托摩尔(10-18)范围内。由于电离过程的选择性，背景噪声被降低，进一步提高了信噪比。这项拟议的研究将涉及利用NCI-MS探索各种电子捕获苯基异硫氰酸酯(PITC)衍生物，并展示一种用于蛋白质和多肽测序的高灵敏度检测方法。蛋白质测序对于理解修饰氨基酸在蛋白质结构中的作用，为克隆基因提供探针，以及划定编码蛋白质的DNA片段的边界都是重要的。这项仪器开发提案还寻求能够使用比目前在微量化学方面所做的努力少得多的材料。

A new method for peptide sequencing will be developed involving negative ion mass spectrometry. Negative chemical ionization mass spectrometry (NCI-MS) can provide the dramatic enhancement in sensitivity necessary to keep pace with the mechanical and engineering improvements in automated protein sequencing. For molecules which are strongly electron-capturing, NCI-MS has been reported to have detection limits in the femtomole to attomole (10-18) range. Because of the selectivity of the ionization process, background noise is diminished, further enhancing signal to noise ratio. The proposed research will involve exploring a variety of electron-capturing phenylisothiocyanate (PITC) derivatives by NCI-MS and demonstrate a highly sensitive detection method for use in protein and peptide sequencing. protein sequencing is important for an understanding of the roles of modified amino acids in protein structure and to provide probes for cloning genes as well as to deliminate the boundaries of DNA segments coding for proteins. This instrument development proposal seeks also to be able to work with far smaller amounts of material than current efforts in microchemistry.