Journal:JBIC:15

Potent Inhibition of Dinuclear Zinc(II) Peptidase, an Aminopeptidase from Aeromonas proteolytica, by 8-Quinolinol Derivatives: Inhibitor Design Based on Zn2+ Fluorophores, Kinetic, and X-ray Crystallographic Study

Kengo Hanaya, Miho Suetsugu, Shinya Saijo, Ichiro Yamato, and Shin Aoki ^[1]

Molecular Tour
The selective inhibition of an , a hydrolase, by derivatives is reported. Based on our findings about 8-HQ-based Zn²⁺ fluorophores, it was hypothesized that 8-HQ derivatives have the potential to function as specific inhibitors of Zn²⁺ enzymes, especially dinuclear Zn²⁺ hydrolases. Inhibitory assays of 8-HQ derivatives against AAP disclosed that the 8-HQ and 5-substituted 8-HQ′s are competitive inhibitors for AAP with inhibition constants (Ki) of 0.16—29 μM at pH 8.0. (1.3 Å resolution) as well as fluorescence titrations of these drugs with AAP confirmed that , in which the in the active site of AAP and the (PDB code: 3vh9). of free AAP (colored green) containing Zn²⁺-bound water molecule (H2O or OH-; red sphere) (1rtq) bridging two Zn²⁺ and AAP–8-HQ complex (darkmagenta, 3vh9). Two Zn²⁺ are depicted as magenta spheres.

PDB reference: Crystal structure of Aeromonas proteolytica aminopeptidase complexed with 8-quinolinol, 3vh9.