i. Quantification of ubiquitin flux in live cells
Developed SILOW Stable Isotopic Labeling with 18O-Water method to quantify flux of
ubiquitination sites in yeast and human cells using LC-MS/MS
Made first observations of proteome-wide ubiquitination site turnover in cells
ii. Steady-state quantification of cellular ubiquitin in each major chemical form i.e. free, thioester - activated, substrate-conjugated
Created and optimized protocols to derivitize ubiquitin
Standardized fluorescence-based assays to quantify ubiquitin using an engineered binding protein