University:
Liberty University
Course:
BIOM 500 | Introduction to Biomedical Sciences
Academic year:

2024
Views:

361

Pages:

5
Author:

Sheha A.

Isoenzymes of Lactate Dehydrogenase and Creatine Phosphokinase Isoenzymes Subunit Constitution Principal Tissue of Origin LDH-1 HHHH Heart & RBC LDH-2 HHHM Heart & RBC LDH-3 HHMM Heart & Kidney LDH-4 HMMM Liver and Kidney LDH-5 MMMM Skeletal Muscle CPK-1 BB Heart CPK-2 MB Heart and Skeletal Muscle CPK-3 MM Skeletal Muscle Properties of Isoenzymes Alternative forms of enzymes Exist in different tissues Differ in amino acid sequence and charge Can be separated electrophoretically Both catalytic and diagnostic properties differ Helps in diagnosis of disease Isoenzymes of Lactate Dehydrogenase and Creatine Phosphokinase Isoenzymes Different amino acid compositions Differ in their physicochemical properties which include molecular size, electrophoretic and immunological properties. Diagnostic Significance of Isoenzymes As almost every biochemical reaction is catalyzed by a specific type of enzyme, and alteration in the activity of an enzyme leads to a cascade reaction of biochemical substrates. Diagnostic Significance of Isoenzymes Has been focal in the diagnosis of various diseases. Has been helpful in the diagnosis of cardiac diseases. Also been used in forecasting of enzymes. Serum Enzymes in Heart Diseases When electrocardiogram (ECG) is difficult to interpret, then enzyme assays are carried out for the diagnosis of myocardial infarction. The enzymes for diagnosis of myocardial infarction are: Creatine phosphokinase Aspartate transaminase Lactate dehydrogenase