biostudies-literatureUnknown59(40)Bi DHoward Hughes Medical InstituteOsteopathic Heritage FoundationSirtuin isoform 2 (SIRT2) is an enzyme that catalyzes the removal of acyl groups from lysine residues. SIRT2's catalytic domain has a hydrophobic tunnel where its substrate acyl groups bind. Here, we report that the fluorescent probe 1-aminoanthracene (AMA) binds within SIRT2's hydrophobic tunnel in a substrate-dependent manner. AMA's interaction with SIRT2 was characterized by its enhanced fluorescence upon protein binding (>10-fold). AMA interacted weakly with SIRT2 alone in solution (<i>K</i>_d = 37 μM). However, when SIRT2 was equilibrated with a decanoylated peptide substrate, AMA's affinity for SIRT2 was enhanced ∼10-fold (<i>K</i>_d = 4 μM). The peptide's decanoyl chain and AMA co-occupied SIRT2's hydrophobic tunnel when bound to the protein. In contrast, bindingBiochemistry3869-3878https://www.ebi.ac.uk/biostudies/studies/S-EPMC7880049biostudies-literatureSubstrate-Dependent Modulation of SIRT2 by a Fluorescent Probe, 1-Aminoanthracene.PMC7880049Hinds NYang JBi DInfanti JHong JYParikh PLin HWeiser BPfalseSubstrate-Dependent Modulation of SIRT2 by a Fluorescent Probe, 1-Aminoanthracene.Sirtuin isoform 2 (SIRT2) is an enzyme that catalyzes the removal of acyl groups from lysine residues. SIRT2's catalytic domain has a hydrophobic tunnel where its substrate acyl groups bind. Here, we report that the fluorescent probe 1-aminoanthracene (AMA) binds within SIRT2's hydrophobic tunnel in a substrate-dependent manner. AMA's interaction with SIRT2 was characterized by its enhanced fluorescence upon protein binding (>10-fold). AMA interacted weakly with SIRT2 alone in solution (<i>K</i>_d = 37 μM). However, when SIRT2 was equilibrated with a decanoylated peptide substrate, AMA's affinity for SIRT2 was enhanced ∼10-fold (<i>K</i>_d = 4 μM). The peptide's decanoyl chain and AMA co-occupied SIRT2's hydrophobic tunnel when bound to the protein. In contrast, binding2020-01-01T00:00:00Z2020 Oct2025-04-19T09:42:25.755Z2022-02-11T12:06:04.36ZS-EPMC78800493294100310.1021/acs.biochem.0c00564