MALDI/ION TRAP MASS SPECTROMETER FOR PEPTIDE SEQUENCING

用于肽测序的 MALDI/离子阱质谱仪

• 批准号: 2284172
• 负责人: ROBERT James COTTER
• 金额: $ 18.71万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-01-01 至 1996-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2284172
• 关键词: Herpesviridae; amyloid proteins; biomedical equipment; biomedical equipment development; electrospray ionization mass spectrometry; histocompatibility antigens; ionic bond; ionization; lasers; method development; peptide structure; phosphorylation; protein sequence; virus protein

A novel method for trapping ions in a quadrupole ion trap has been developed, utilizing programmed RF-voltage amplitudes and electrostatic trapping fields applied to the end-cap electrodes and/or the sample probe. This method overcomes the difficulties associated with trapping of the high kinetic energy ions produced by matrix-assisted laser desorption, and has been successful in achieving mass resolutions greater than one part in 12,000 for peptides in the range of 1000 to 1500 DL In addition, the method obviates the need for high pressures of the buffer gas normally used to retard ion velocities and, therefore, permits one to obtain high resolution mass spectra at normal scan rates. Thus far, our work has been carried out on a modified Finnigan ion trap detector (ITD), which does not have the capabilities for detection of high mass ions or for tandem mass spectrometry. We propose, therefore, to further modify the existing ITD vacuum chamber, detection system, and electronics to enable us to extend this approach to peptides in the range of 500 to 4000 daltons, and to carry out tandem experiments to obtain amino acid sequence from the (primarily) singly-charged molecular ions produced by matrix-assisted laser desorption. It is our intention to evaluate this instrumental configuration promptly for the analysis of peptides in ongoing projects of the Middle Atlantic Mass Spectrometry laboratory, with the goal of developing a compact and user-friendly instrument for routine structural analysis of peptides. Thus, the instrument will be utilized for the structural analysis of the beta-amyloid peptides associated with Alzheimer's disease, to determine phosphorylation sites on the Assembly Protein of several herpesviruses, to characterize the peptide antigens associated with the Major Histocompatibility Complex (MHC), and for several other collaborative projects.

提出了一种在四极离子阱中捕获离子的新方法