Therapeutic and Diagnostic Applications of Enzymes and Isoenzymes

Enzymes

Therapeutic application

Human beings use certain enzymes to treat several diseases, such as:

• Certain types of leukemia are treated with bacterial asparginase.
• During lens extraction, chymotrypsin is used to dissolve the ligaments between the lens and the cornea.
• Dermal ulcers and severe burns can be cleaned with collagenase by removing dead tissue.
• The subcutaneous injection of drugs is facilitated with hyaluronidase.
• Penicillinase - Treats patients who have an allergy to penicillin.
• Streptokinase and urokinase - To dissolve purulent material or clot caused by myocardial infractions.
• GIT disorders and chronic pancreatitis are treated with pepsin, lipase, amylase elastase, and trypsin peptidase.

Diagnostic applications

It is known that enzymes are markers of cell damage. It is used to assess liver, heart, skeletal muscle, bile duct and other diseases based on the number of enzymes present in the plasma.

Identifying and classifying enzymes with diagnostic importance

1. Cardiac, liver and skeleton enzyme - Among these enzymes are:

a) Transaminase or aminotransferase

• Aspartate aminotransferase (AST) increases and plasma alanine aminotransferase (ALT) increases indicate liver disease.
• As AST concentration in heart muscle is relatively high after myocardial infraction, AST level increases.
• In muscular dystrophy and dermatomyositis, AST activity levels are elevated.
• Alcohol consumption or the consumption of various drugs like salicylates, ampicillin, etc. are associated with moderate increases in AST and ALT.

b) Alkaline phosphate - An ALP level in the plasma is particularly useful in the diagnosis of bone and hepatic conditions.

2. Digestive enzymes of pancreatic origin - This category contains enzymes such as

• In hepatobiliary diseases in which bile secretion is obstructed, 5'-nucleotidase (nucleotide phosphate NTP) levels are elevated.
• Gamma-glutamine transferase GGT- Increased levels of GGT occur when the liver is ill with any type of disease. These tests are used to detect obstructive jaundice, cholecystitis (inflammation of the gall bladder) and cholangitis (inflammation of the bile ducts).

3. Biliary track enzymes - Diagnostic tests are performed on digestive enzymes to diagnose pancreatic diseases

• Alpha amylase - Amylase measurements in the serum and urine are typically used to diagnose pancreatic diseases like pancreatitis, cholecystitis, or tumors.
• Trypsin - During the first six weeks after birth, serum trypsin levels can be measured to screen for cystic fibrosis. Pancreatic ductulus are also screened with serum trypsin.
• Chymotrypsin - A serum chymotrypsin level exceeding eight times the normal value indicates renal failure, as with amylase and trypsin.

Isoenzymes

Molecular markers of tissue damage are available through serum enzymes and isoenzymes, which are of clinical interest. Enzymes cannot normally pass through the membranes of cells, so enzyme activity in the serum is lower than in cells.

Isoenzymes (also known as isozymes) are enzymes with different amino acid sequences that catalyze the same chemical process. The properties of these enzymes can be different kinetic parameters (e.g., different KM values), or they can reflect different regulatory properties as well. Isozymes enable metabolism to be fine-tuned for tissues or stages of development (for example, lactate dehydrogenase (LDH)). An isozyme (or isoenzyme) is a variant of an enzyme that is closely related to another. Homologous genes have diverged over time, and they often encode for the same thing. The two words are often used interchangeably, even though allozymes represent different alleles of the same gene, whereas isozymes represent different genes whose products catalyze the same reaction.

Isozymes can be identified by their differences, such as glucokinase, a variant of hexokinase that is not inhibited by glucose 6-phosphate. Different regulatory features, and a lower affinity for glucose (relative to other hexokinases), allow them to serve different functions in different organ cells. For example, beta cells of the pancreas secrete insulin, while liver cells synthesize glycogen. If glucose levels are low, or problems develop, both of these processes cannot take place.

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