Mechanisms of disease

3. Targets for action of medicines

3.3. Enzymes

A third group of medicine targets are ‘enzymes. These proteins facilitate (catalyse) chemical processes within the body (e.g. in body fluids such as ‘blood plasma’). The hormone GLP-1 is a good example. GLP-1 assists the secretion of insulin, which is involved in reducing blood glucose levels. However, GLP-1 can be quickly broken down in blood plasma by a specific enzyme. By introducing a medicine that inhibits this enzyme, the natural GLP-1 molecule is active long enough to work. This can help to reduce symptoms linked to high blood sugar levels.