6.6 Isozymes

In this video, we explain what are isozymes and how they help the body regulate metabolism. Lactate dehydrogenase and hexokinase isozymes are used to explain the differences and similarities between isozymes and why different isozymes work better in different tissue environments, and why a certain isozyme may be more suited for the organ's function (example , why glucokinase is better for liver function than other HK isozymes). Clinical applications of isozymes is discussed next using examples of LDH and creatine kinase (CK) for myocardial infarction, phosphodiesterase for treatment of erectile dysfunction by the drug Viagra, cytochrome P450 isozymes for drug metabolism, and importance of isozymes in genetic diseases such as aldolase A deficiency (type 12 glycogen storage disease) and muscle PFK deficiency (type VII glycogen storage disease)