L-Azidohomoalanine (AHA) is an amino acid analog of methionine that contains a very small modification, specifically an azido moiety that can be fed to cultured cells and incorporated into proteins during active protein synthesis. Detection utilizes the chemoselective ligation or “click ” reaction between an azide and an alkyne or cyclooctyne. The azido-modified protein is detected with either fluorescent alkyne or biotin alkyne. Detection sensitivity with these reagents in 1-D gels and Western blots is in the low femtomole range and compatible with downstream LC-MS⁄MS and MALDI MS analysis.
1. Tao, W.A., et al. (2019). Identification and Quantification of Newly Synthesized Proteins Using Mass Spectrometry‐Based Chemical Proteomics. Mass Spectrometry‐Based Chemical Proteomics. [PubMed]