Enzymes are specialized proteins that function as biological catalysts, significantly speeding up biochemical reactions within the body. These reactions are essential for maintaining life, supporting processes ranging from digestion to energy production. Enzymes are crucial for the proper functioning of cells, tissues, and organs, thereby contributing to overall health.
Enzymes for Disease Detection
Medical professionals frequently use the presence, absence, or altered levels of specific enzymes in bodily fluids to diagnose various health conditions. Certain enzymes serve as biomarkers, indicating organ damage or disease. When cells are injured or die, they often release their internal enzymes into the bloodstream, where their levels can be measured.
For example, cardiac enzymes, such as troponin I and troponin T, indicate heart muscle damage. Elevated levels in blood tests can confirm a heart attack, with higher concentrations correlating to more severe injury. Creatine kinase-MB (CK-MB) is another cardiac enzyme that can indicate heart damage.
Liver enzymes like alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) are markers for liver health. Elevated levels suggest liver damage or disease, as they leak into the bloodstream when liver cells are compromised. Similarly, amylase and lipase are enzymes produced by the pancreas. Abnormally high levels, particularly lipase, indicate acute pancreatitis, an inflammation of the pancreas.
Enzymes as Direct Therapies
Enzymes are administered as direct treatments for various medical conditions. Enzyme replacement therapy (ERT) is a prominent example, used for genetic disorders where the body lacks a functional enzyme. In conditions like Gaucher disease, ERT replaces the deficient enzyme glucocerebrosidase, preventing the harmful buildup of substances in the body and improving patient quality of life.
Digestive enzyme supplements, such as pancrelipase, are prescribed for individuals with pancreatic insufficiency or cystic fibrosis. These supplements contain enzymes like amylase, lipase, and protease to aid in breaking down carbohydrates, fats, and proteins, improving nutrient absorption. Thrombolytic enzymes, like alteplase and streptokinase, are “clot-busting” drugs that dissolve dangerous blood clots in conditions such as heart attacks or strokes.
Enzymes also play a role in wound care. Collagenase is an enzyme used for enzymatic debridement, removing necrotic (dead) tissue from wounds without harming healthy tissue. Enzymes like asparaginase are used in specific cancer therapies, particularly for acute lymphoblastic leukemia, by depleting an amino acid essential for cancer cell survival.
Modifying Enzyme Action for Treatment
Many common medications achieve their therapeutic effects by modifying the action of the body’s own enzymes. This often involves inhibiting specific enzymes to interrupt disease pathways.
ACE inhibitors, used to treat high blood pressure and heart failure, block the angiotensin-converting enzyme. This action prevents the formation of a substance that narrows blood vessels, leading to lower blood pressure. Statins, a class of cholesterol-lowering drugs, inhibit the enzyme HMG-CoA reductase, reducing cholesterol levels in the blood.
Nonsteroidal anti-inflammatory drugs (NSAIDs) reduce pain and inflammation by inhibiting cyclooxygenase (COX) enzymes, which are involved in the production of inflammatory compounds. Proton pump inhibitors (PPIs) reduce stomach acid in conditions like acid reflux. These drugs block the H+/K+-ATPase, or gastric proton pump, the final step in acid secretion by stomach cells.
While enzyme inhibitors are more common, some treatments can enhance enzyme activity. This strategy of targeting enzymes provides a powerful means for medical intervention.