Individual Ion Mass Spectrometry of p53
In collaboration with:
Description: p53 has >100 potential PTM sites. The substantial crosstalk among PTM sites somehow underlies its ability to integrate diverse signals and coordinate effector functions. Previous interrogation of p53 by immunoprecipitation coupled with top-down mass spectrometry failed to identify the combinatorial modifications that comprise p53 proteoforms. Individual ion mass spectrometry (I2MS) is an emerging data acquisition approach that bypasses prior limitations of denatured top-down mass spectrometry. I2MS removes the ~30 kDa upper limit of data acquisition, thereby enabling improved results for the complex case of p53.
Endogenous p53 is isolated from cancer cell lines by immunoprecipitation with magnetic beads. The proteoform landscape of p53 is too complex to be effectively captured by ensemble mass spectrometry measurement. Instead, intact mass spectrometry data is collected with individual ion mass spectrometry in which individual ions are assigned charge to assemble a mass spectrum. These measurements show significant dynamics modifications of p53. Credit: Bryon Drown.
Project status: On going
– ASMS 2021
Spinoff funding: R01