Related Experiment Video
Updated: Aug 31, 2025

Hot Biological Catalysis: Isothermal Titration Calorimetry to Characterize Enzymatic Reactions
Published on: April 4, 2014
Inhibition of Urease by Hydroquinones: A Structural and Kinetic Study
Luca Mazzei1, Michele Cianci2, Stefano Ciurli1
1Laboratory of Bioinorganic Chemistry Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Viale Giuseppe Fanin 40, 40127, Bologna, Italy.
Abstract:
Hydroquinones are a class of organic compounds abundant in nature that result from the full reduction of the corresponding quinones. Quinones are known to efficiently inhibit urease, a NiII -containing enzyme that catalyzes the hydrolysis of urea to yield ammonia and carbonate and acts as a virulence factor of several human pathogens, in addition to decreasing the efficiency of soil organic nitrogen fertilization. Here, we report the molecular characterization of the inhibition of urease from Sporosarcina pasteurii (SPU) and Canavalia ensiformis (jack bean, JBU) by 1,4-hydroquinone (HQ) and its methyl and tert-butyl derivatives. The 1.63-Å resolution X-ray crystal structure of the SPU-HQ complex discloses that HQ covalently binds to the thiol group of αCys322, a key residue located on a mobile protein flap directly involved in the catalytic mechanism. Inhibition kinetic data obtained for the three compounds on JBU reveals the occurrence of an irreversible inactivation process that involves a radical-based autocatalytic mechanism.
Related Concept Videos
Enzyme Inhibition
The Electron Transport Chain
Inhibitors of the electron transport chain
Rotenone, a widely used pesticide, prevents electron transfer from Fe-S cluster to ubiquinone or Q...
Indirect-Acting Cholinergic Agonists: Mechanism of Action
Reversible inhibitors like edrophonium bind to a specific part of the enzyme called the anionic catalytic site. They form noncovalent bonds, which means they are not strongly attached to the enzyme. This creates a temporary and less stable enzyme–inhibitor complex,...
Indirect-Acting Cholinergic Agonists: Chemistry and Structure-Activity Relationship
Reversible inhibitors display short to medium durations of action. Short-acting agents include simple alcohols with...
Acid Suppressive Drugs for Peptic Ulcer Disease: Proton Pump Inhibitors
Gastric acid, a potent cocktail of hydrogen and chloride ions, is produced in specialized parietal cells within the...
Gene Regulation in Microbial Communities: Quorum Sensing

