Description
Insulin is a peptide hormone produced exclusively by beta cells of the pancreatic islets. The mature form of insulin is a heterodimer of a B chain and an A chain linked by two disulfide bonds. The amino acid sequence of insulin is strongly conserved and varies only slightly between species. Bovine insulin differs from human in only three amino acid residues, and porcine insulin in one. Insulin is considered to be the main anabolic hormone of the body and regulates the metabolism of carbohydrates, fats and protein by promoting the absorption of glucose from the blood into liver, fat and skeletal muscle cells. Decreased or absent insulin activity results in diabetes. Recombinant insulin has been widely used for treatment of diabetes.