Enzymology

This course provides fundamental knowledge of formal and structural enzymology.

- The first part of this course covers formal kinetics (the study of reaction rates, determining the order of a reaction, equilibrium and kinetics, reversible and equilibrated reactions). The experimental aspects are presented in parallel (determining kinetic constants using spectrophotometry, fluorescence, radioactivity, immunoassays, etc.).

- The second part of the course focuses on the study of single-substrate enzyme kinetics.

Definition of an enzyme, a catalyst. Enzyme classification (EC)

Michaelis kinetics. Michaelis-Menten equation. Definition of enzymatic parameters:_KM, maximum velocity, catalytic constant, turnover. Various graphical representations (Lineweaver-Burk, Eadie-Hofstee). 

The different types of inhibition are also studied (competitive, uncompetitive, noncompetitive, mixed), as well as their graphical representation.

Determination of the inhibition constant. Irreversible inhibitors.

Reaction rate. Arrhenius's law.

- The third section focuses on describing multi-substrate enzyme kinetics from a formal perspective. Including ternary complexes. Random or ordered mechanisms.

Without a ternary complex. Ping-Pong mechanism, Theorell-Chance mechanism. Cleland representation.

Graphical determination.

- Part 4 covers equilibrium binding and allosterism.

Receptor-Ligand / Enzyme-Substrate Binding. Determination of the dissociation (or association) constant. Specific and nonspecific binding.

Scatchard's demonstration and graphical representation. Allosteric receptors (or enzymes). Non-Michaelis enzyme. Concept of cooperativity. Positive and negative cooperativity. Hill number, Hill plot.

Allosteric regulation models are presented. Allostery. Models of cooperativity: concerted (Monod-Wyman-Changeux) and sequential (Koshland-Nemethy-Filmer). Role of effectors: activators or inhibitors. Example of hemoglobin and oxygen binding.

- The fifth part of the course explores the relationship between enzyme structures and their functions using several examples. It describes the 3D structures and catalytic mechanisms of acetylcholine esterase, proteases, and nucleoside diphosphate kinase. It also covers concepts such as the catalytic triad, the binding pocket, and more. 

By the end of this course, students should be able to analyze and interpret

enzymatic experimental data and be able to describe all mechanisms, with or without effectors. He or she must know how to calculate the various kinetic parameters and place them in the context of metabolism as a whole. He or she will be able to analyze and relate the structure and function of enzymes and describe the molecular steps of a catalytic mechanism