<p><i>N</i>ε-methylation of lysine within proteins is a critical biological process that, among other roles, is involved in the control of gene expression. Compounds that recognise <i>N</i>ε-methylated lysine may therefore be useful probes for the study of the associated biological mechanisms and have therapeutic potential. Here, we show that tetracyanoresorcin[4]arene (<b><i>1</i></b>) selectively recognises <i>N</i>ε-trimethyllysine and binds to <i>N</i>ε-trimethyllysine within the context of a short peptide. Its binding properties compare favourably to a previously characterised <i>N</i>ε-trimethyllysine binder, <i>p</i>-sulfonatocalix[4]arene (<b><i>2</i></b>). We also show that both <b><i>1</i></b> and <b><i>2</i></b> inhibit the demethylation of <i>N</i>ε-trimethyllysine within a histone-derived peptide by the histone demethylase KDM4A.</p
