Fundamentals of Enzymology and Classification
The branch of biochemistry that studies the structure, properties, and mechanism of action of enzymes is called enzymology. In medical practice, three main areas are distinguished:
- Enzymopathology — the study of enzyme activity disorders as causes of pathologies.
- Enzymodiagnostics — measuring enzyme activity in biological fluids to detect diseases.
- Enzymotherapy — the use of enzymes and their regulatory components as medications.
The main components of reactions are the substrate (S), which is converted by the enzyme (E), and the resulting product (P).
Structural Nature of Enzymes
Most enzymes consist of protein molecules and exhibit all their properties. A historically important milestone was the discovery by J. Sumner, who in 1926 isolated crystalline urease, an enzyme that breaks down urea into ammonia and carbon dioxide. Later, in the 1930s, trypsin and pepsin were also obtained in crystalline form. In addition to protein structures, ribozymes—special RNA molecules—can also possess catalytic activity.
Mechanisms of Cellular Regulation and the Caspase Cascade
A crucial example of an enzymatic cascade in pathogenesis is apoptosis, programmed cell death. A key role here is played by caspases, cysteine proteases that cleave proteins at aspartic acid residues.
| Caspase Type | Function in the Cascade |
|---|---|
| Regulatory | Initiation of the Apoptotic Cascade |
| Integrative | Effector Degradation of Cellular Targets |
Caspase activation triggers the destruction of cytoskeletal and nuclear proteins and activates nucleases that cleave DNA.
Enzymology studies E (enzymes), which convert S (substrates) into P (products).
Class and exam questions
What is enzymology, and what areas are distinguished within it?
This is a branch of biochemistry that studies the properties, structure, and mechanism of action of enzymes. Enzymopathology, enzymodiagnostics, and enzymotherapy are distinguished.
What is the chemical nature of most enzymes?
Most enzymes are globular proteins with a molecular weight of 10⁴–10⁶ Da. At the same time, certain RNA molecules—ribozymes—also possess catalytic activity.
What are caspases, and what is their role?
Caspases are cysteine proteases that cleave proteins at aspartic acid residues. They trigger a cascade of reactions leading to the destruction of cellular targets and apoptosis.
What else to study on this topic
- Mitochondrial Pathway of Apoptosis and the Role of Cytochrome c
- Formation and Structure of the Apoptosome
- Involvement of the Bcl-2 Family of Proteins in the Regulation of Cell Death
- Mechanism of Action of Ca²⁺, Mg²⁺-Dependent Endonucleases
- The Role of Cytotoxic T Lymphocytes and Granzymes
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