Analysis of individual protein turnover in live animals on a proteome-wide scale

Classical quantitative proteomics studies focus on the relative or absolute concentration of proteins at a given time. In contrast, the investigation of protein turnover reveals the dynamics leading to these states. Analyzing the balance between synthesis and degradation of individual proteins provides insights into the regulation of protein concentration and helps understanding underlying biological processes. Comparing the half-lives of proteins allows detecting functional relationships and common regulation mechanisms. Moreover, comparing turnover of individual brain and plasma proteins between control- and treatment-groups indicates turnover changes induced by the treatment.Here, we describe a procedure for determining turnover information of individual proteins in mice on a proteome-wide scale based on partial (15)N metabolic labeling. We will outline the complete experimental workflow starting from (15)N labeling the animals over sample preparation and mass spectrometric measurement up to the analysis of the data.