Time-of-flight mass spectrometry of biomolecules using particle and laser induced desorption

点击翻译按钮获取中文摘要

The dramatic developments in gene technology, and the completion of genome sequences for a variety of organisms, including humans, provide unprecedented opportunities for rapid and sensitive determination of the identity and function of proteins. In this field of proteomics, mass spectrometry plays a pivotal role, due to similarly dramatic developments in this field, many of them in physics laboratories. In the late 80s, limited accessible mass range and sensitivity were largely overcome by the invention of two new ionization techniques, matrix-assisted laser desorption/ionization (MALDI), and electrospray ionization (ESI). The 2002 Nobel prize in Chemistry was awarded in part for these developments. The broad objectives of our research are to study, develop, and apply methods of mass spectrometry for large molecules, particularly biomolecules. Orthogonal-injection MALDI TOF and the corresponding application of MS/MS using a quadrupole/TOF geometry, were first demonstrated in our laboratory, and have become standard techniques in proteomics research. The particular focus of this project is to study the physical mechanisms involved in the desorption of large molecules by laser and particle desorption and to develop improved methods for mass selected imaging of biological tissue. Many of the recent improvements in analyzing ions produced by MALDI, such as delayed extraction and orthogonal-injection depend critically on knowledge of the ejection dynamics, with and without an extraction field, and we propose to continue our work on such studies using both axial and orthogonal injection TOF instruments.