Table 3 A subset of tryptic peptides from glyceraldehyde-3-phosphate dehydrogenase C subunit (At3g04120) that were identified by mass spectrometry and subsequent database search (¹⁴N-search, see methods for details). For each peptide the expected mass difference was calculated based on the measured mass to charge ratio (MCR). Asterisks mark those peptides that have also been identified in the database search with ¹⁵N as fixed modification (¹⁵N-search, see Methods for details)

From: Metabolic labeling of plant cell cultures with K¹⁵NO₃ as a tool for quantitative analysis of proteins and metabolites