izoenzimváltozata

Isoenzyme variation refers to the existence of different molecular forms of an enzyme within the same organism or even within the same cell. These different forms, known as isoenzymes or isozymes, catalyze the same biochemical reaction but differ in their amino acid sequence, and consequently, in their physical and chemical properties such as electrophoretic mobility, kinetic parameters, and optimal pH. This variation arises from differences in the genes encoding the enzyme subunits or through post-translational modifications.

The functional significance of isoenzyme variation lies in their ability to adapt enzymatic activity to specific cellular conditions or tissues. For instance, different isoenzymes of lactate dehydrogenase (LDH) are expressed in different tissues like the heart and skeletal muscle, with their distinct kinetic properties allowing for optimal function under varying oxygen availability. This tissue-specific expression allows for fine-tuning of metabolic pathways.

The study of isoenzymes has important diagnostic applications. Elevated levels or altered patterns of specific isoenzymes in biological fluids like blood can indicate tissue damage or disease. For example, specific LDH isoenzymes are used as markers for myocardial infarction. Similarly, variations in isoenzymes like creatine kinase (CK) can help differentiate between muscle damage from various causes. Understanding isoenzyme variation is crucial for comprehending enzyme regulation, cellular function, and the diagnosis of a range of medical conditions.