Fig. 4: Amino acid selectivity of electrophiles targeting lysines, protein N-termini, aspartates and glutamates.
From: Profiling the proteome-wide selectivity of diverse electrophiles
a,c–g,j,k Structures of alkyne probes containing or producing activated ester (a), squaric acid ester (c), ethynylbenzaldehyde (d), nitrosobenzaldehyde (e), heteroaryl aldehyde (f), nitrilimine (g), ketoketenimine (j) or azirine (k) electrophiles that were investigated with respect to their proteome-wide amino acid selectivity. Orange circles indicate the initial site of electrophilic reactivity. For probes oNBA-alkyne, PhTet-alkyne, AmTet-alkyne, MeTet-alkyne, HC-alkyne and Isx-alkyne, the reactions leading to the reactive intermediate are also shown. b,h,i, Amino acid selectivity of probes targeting lysines (b), N-termini (h) or carboxylic acid residues (i) upon treatment of the proteome of S. aureus SH1000 at 100 µM probe concentration. The data are represented as letter plots, in which the size of each letter is scaled by the fraction of all modified sites that were modified at the indicated amino acid. All amino acids that were modified in fewer than 5% of cases are summarized as ‘Others’. The total numbers of modified sites are given as a bar graph on top of the letter plot. aLabelling was performed using UV activation at 280–315 nm (PhTet-alkyne, AmTet-alkyne and MeTet-alkyne) or 365 nm (oNBA-alkyne) for 10 min. bData for the indicated probe at 1 mM are shown. All data are based on technical duplicates.
