N-Myristoyl Transferase (NMT)-Catalyzed Labeling of Bacterial Proteins for Imaging in Fixed and Live Cells

Abstract

Methods for selective protein imaging are critical for elucidating how cells orchestrate fundamental biological processes. We recently developed a chemoenzymatic method to modify bacterial proteins in situ for fluorescence imaging using N-myristoyl transferase (NMT). Target proteins outfitted with an N-terminal NMT recognition sequence are covalently modified with an azido fatty acid. Subsequent strain-promoted azide–alkyne cycloaddition allows for conjugation to cell-permeant fluorophores and imaging by fluorescence microscopy. Here we describe sample preparation and labeling protocols for imaging bacterial proteins in fixed and live cells.