使用LTQ的MS/MS和MS3鉴定及定量iTRAQ标记肽段
简介：
This new method utilizes MSn for direct analysis ofi TRAQ labels using the LTQ, with peptide identification in the MS/MS scan and quantitation of the tag in a subsequent, MS3 scan. This method was firstdescribed by Carr et al. at ASMS 2005 in San Antonio, Texas.4 (Note: A new ionization technique, called pulsed-Q dissociation (PQD) was ntroduced by Thermo FisherScientific at ASMS 2005. PQD eliminates the “1/3 Rule” for the LTQ. Use of this echnique for iTRAQ analysis and other applications will be described in a future Application Note.)
仪器：
iTRAQ reagent
结论：
The method proposed by Carr et al5 for relative quantitation with iTRAQ works well on the LTQ linear ion trap. regating peptide identification in one scan mode (MS/MS) and iTRAQ quantification in another scan mode (MS3) allows both functions to be performed well.
The C-terminal lysine peptides in the six protein digest ranged in size from 7 to 22 residues with varying degrees of basicity. No problems were observed in the generation of y-1 ions from these peptides, nor were any problems observed with the release of the labile iTRAQ tags.
