LTQ FT ECD自上而下地分析完整蛋白质

　简介：Electron capture dissociation (ECD), an ion fragmentation technique in FTICR mass spectrometry,1-3 has emerged as a powerful method for top-down protein identification and characterization. When compared to other fragmentation techniques, such as collision activated dissociation (CAD) and infrared multiphoton dissociation (IRMPD), ECD demonstrates unique capabilities including extensive backbone cleavage, retention of post-translational modification location information, disulfide bond cleavage and side chain cleavage.4 In this report we use a Thermo Scientific LTQ FT equipped with ECD to perform topdown analysis of three intact proteins: equine myoglobin, human apolipoprotein A-1, and bovine carbonic anhydrase II. The ECD MS/MS spectra of all three proteins provide the high level of sequence coverage necessary for protein characterization. In this report we demonstrate how the high fragmentation efficiency of ECD combined with the ease of use, high mass resolution and high mass accuracy of the LTQ FT mass spectrometer permits routine use of this fragmentation technique as an indispensable tool for top-down protein characterization.

仪器：LTQ FT/ECD

结论：In this report we have demonstrated that ECD fragmentation is useful in providing extensive backbone fragmentation of intact proteins, which is valuable for the protein characterization particularly when combined with the high mass accuracy of the LTQ FT.

With the configuration of both ECD and IRMPD available on the LTQ FT, it is possible to do “activated ion ECD” (AI-ECD) by first activating the ions with the IR laser and then dissociate them by ECD. This enables ECD to provide more extensive, and complementary sequence information.

Additional information regarding IRMPD and ECD can be found in Application Note 30099, Unfolding of Intact Ubiquitin in the Gas Phase by IRMPD and Fragmentation with ECD.