15N Metabolic Labeling of Mammalian Tissue with Slow Protein Turnover

Abstract

We previously reported the metabolic ¹⁵N labeling of a rat where enrichment ranged from 94% to 74%. We report here an improved labeling strategy which generates 94% ¹⁵N enrichment throughout all tissues of the rat. A high ¹⁵N enrichment of the internal standard is necessary for accurate quantitation, and thus, this approach will allow quantitative mass spectrometry analysis of animal models of disease targeting any tissue. Keywords: Brain • Proteomics • Quantification • Labeling • SILAM