Enzyme as Drug Target

Study Notes

Enzyme as Drug Target

Enzymes are globular proteins that function as biological catalysts, speeding up reactions and lowering activation energy.
Enzyme names typically end with the suffix “-ase”.
Lactate dehydrogenase (LDH) is an example, converting pyruvic acid to lactic acid with NADH as a cofactor.
The Gibbs free energy change (∆G) remains constant, regardless of the enzyme's presence; enzymes only lower activation energy.

Structure and Function of Enzymes

Enzymes consist of an active site that is a hydrophobic cleft, crucial for substrate binding.
The active site is composed of amino acids that interact with substrates and cofactors, facilitating catalytic reactions.

Active Site Dynamics

Active sites accommodate reactants (substrates and cofactors) and participate directly in the reaction process.
Binding of substrates often involves intermolecular bonds and can induce conformational changes in the enzyme, known as the "induced fit" model.

Substrate Binding Mechanisms

Induced fit mechanism: the active site shape closely resembles the substrate before binding, which alters upon substrate interaction to enhance fit.
Bonding forces during substrate binding include van der Waals interactions and other intermolecular bonds that stabilize the enzyme-substrate complex.

Types of Enzyme Inhibitors

Reversible inhibitors: bind to enzymes temporarily and can easily dissociate, restoring enzyme activity.
Irreversible inhibitors: form permanent bonds, leading to long-lasting inhibition of enzyme function.
Allosteric inhibitors: bind to sites other than the active site, causing conformational changes that decrease enzyme activity.
Transition state inhibitors: mimic the transition state of the substrate to effectively block the enzyme's active site.

Therapeutic Targets

Understanding enzyme structure, function, and regulation provides pathways for developing medications targeting specific enzymes to treat various conditions.

Description

This quiz explores the role of enzymes as drug targets, their structure, and how they function as biological catalysts. It covers key concepts such as active site dynamics, substrate binding, and the impact on reaction rates. Test your knowledge of enzymatic mechanisms and their significance in pharmacology.