Related Experiment Video
Updated: Jul 16, 2026

Click-Chemistry Based Fluorometric Assay for Apolipoprotein N-acyltransferase from Enzyme Characterization to High-Throughput Screening
Published on: May 13, 2020
Selectivity of microbial acyl-CoA: cholesterol acyltransferase inhibitors toward isozymes
Taichi Ohshiro1, Lawrence L Rudel, Satoshi Omura
1Kitasato Institute for Life Sciences, Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan.
Abstract:
The selectivity of microbial inhibitors of acyl-CoA: cholesterol acyltransferase (ACAT) toward the two isozymes, ACAT1 and ACAT2, was assessed in cell-based assays. Purpactin A (IC50 values of ACAT1 vs. IC50 values of ACAT2; 2.5 microM vs. 1.5 microM), terpendole C (10 microM vs. 10 microM), glisoprenin A (4.3 microM vs. 10 microM), spylidone (25 microM vs. 5.0 microM) and synthetic CL-283,546 (0.1 microM vs. 0.09 microM) inhibited ACAT1 and ACAT2 to similar extents. Beauveriolides I (0.6 microM vs. 20 microM) and III (0.9 microM vs. >20 microM) inhibited ACAT1 rather selectively, while pyripyropenes A (>80 microM vs. 0.07 microM), B (48 microM vs. 2.0 microM), C (32 microM vs. 0.36 microM) and D (38 microM vs. 1.5 microM) showed selective inhibition against ACAT2. In particular, pyripyropene A was found to be the most selective ACAT2 inhibitor with a selective index of more than 1,000.
Related Concept Videos
Enzyme Inhibition
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...
Inhibitors of Bacterial Protein Synthesis
Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes

