Abstract

An approach to proteomic analysis that combines bioorthogonal noncanonical amino acid tagging (BONCAT) and pulsed stable isotope labeling with amino acids in cell culture (pSILAC) provides accurate quantitative information about rates of cellular protein synthesis on time scales of minutes. The method is capable of quantifying 1400 pro-teins produced by HeLa cells during a 30min interval, a time scale that is inaccessible to isotope labeling techniques alone. Potential artifacts in protein quantification can be reduced to insignificant levels by limiting the extent of non-canonical amino acid tagging. We find no evidence for ar-tifacts in protein identification in experiments that combine the BONCAT and pSILAC methods. Molecular & Cellular