Kinetic Modeling of Time-Dependent Enzyme Inhibition by Pre-Steady-State Analysis of Progress Curves: The Case Study of the Anti-Alzheimer’s Drug Galantamine

• DOI: 10.3390/ijms23095072
• Publication Date: 2022-05-03T12:26:35Z
• Authors: Doriano Lamba; Alessandro Pesaresi
• Keywords: Galantamine; Enzyme Inhibition; State dependent

The Michaelis-Menten model of enzyme kinetic assumes the free ligand approximation, steady-state approximation and rapid equilibrium approximation. Analytical methods to slow-binding inhibitors by analysis initial velocities have been developed but, due their inherent complexity, they are seldom employed. In order circumvent complications that arise from violation assumption, inhibition is commonly evaluated pre-incubating so that, even for slow inhibitors, binding established before reaction started. Here, we show long drug-target residence time conventional linear regression double-reciprocal plots fails provide a correct description mechanism. As case study, acetylcholinesterase galantamine, drug approved symptomatic treatment Alzheimer's disease, reported. For over 50 years, based on has overlooked time-dependent nature galantamine inhibition, leading an erroneous assessment potency and, hence, discrepancies between biochemical data pharmacological evidence. Re-examination pre-steady state progress curves showed indeed underestimated factor ~100.