Scheme 1.

Nomenclature for the series of probes and competitors prepared in this study: (A) Sequences of the photo cross‐linkable and clickable decamer peptide probes based on H4, H3, TNF‐α, and CPS‐1 sequences (1 – 4, respectively). (B) Structures of the posttranslationally modified lysine residues A–C. (C) Structures and abbreviations for the investigated PTMs. (D) Competitor sequences, lacking photo cross‐linker and click handle, are named similar to the probes but marked with a “C” in superscript 1^C, 3^C, 4^C.