Selective N-terminal fluorescent labeling of proteins using 4-chloro-7-nitrobenzofurazan: A method to distinguish protein N-terminal acetylation

ArticleinAnalytical Biochemistry 428(1):13-5 · June 2012with3 Reads
Impact Factor: 2.22 · DOI: 10.1016/j.ab.2012.05.026 · Source: PubMed


    A fluorogenic derivatization method was developed to distinguish the protein N-terminal acetylation status. The unacetylated protein selectively reacted with 4-chloro-7-nitrobenzofurazan (NBD-Cl) at neutral pH to provide high fluorescence. In contrast, the protein with N-terminal acetylation was essentially nonfluorescent under the same conditions despite the presence of many internal lysine residues. Fluorescence of the NBD-labeled protein was very stable, and only micromolar concentrations of proteins were required for reliable detection. This method also provides a general and practical way to quantify proteins when their N-terminal amino group is available.