Related Experiment Video
Updated: Aug 26, 2026

The Importance of Correct Protein Concentration for Kinetics and Affinity Determination in Structure-function Analysis
Published on: March 17, 2010
Thiirancarboxamides as inhibitors of papain
Gemma Bruno1, Tanja Schirmeister
1Department of Chemistry and Pharmacy, Institute of Pharmacy and Food Chemistry, Wuerzburg, Germany.
Abstract:
Derivatives of the thiirancarboxylic acid building-block containing a peptide bond were synthesised and screened against the model cysteine protease papain. The most active of the series showed a second-order rate constant of inactivation comparable to that of the parent compound. The insertion of a peptide moiety seems to compensate the lack of a free carboxylate interacting with the histidinium ion at the enzyme's active site.
Related Concept Videos
Allosteric Proteins-ATCase
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
Anthelminthic Agents
Caspases
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, leading to...
Dipeptidyl Peptidase 4 Inhibitors
Enzyme Inhibition
