Chemical Composition and Structure

Human Growth Hormone, specifically somatotropin, is a molecule composed of 191 amino acids arranged into a single polypeptide chain. It is chemically composed of; Oxygen, Carbon, Hydrogen, Nitrogen and Sulphur. Its polypeptide chain is folded into a specific three-dimensional structure and is held together by intramolecular forces, hydrophobic interactions and more specifically two disulfide bonds between cysteine residues located near the protein’s C-terminus. The structure of human growth hormone is crucial in determining its function. Secondary protein structures such as alpha-helices and beta-sheets are conformed to interact with and bind to growth hormone receptors on the surface of target cells to induce a specific response relating to the following:

• Growth
• tissue repair 
• metabolic processes​

How is Human Growth Hormone Made

As previously stated, human growth hormone can be both naturally and synthetically produced. Its natural production occurs in the pituitary gland located in the brain. This process is activated by growth hormone-releasing hormone and inhibited by somatostatin binding to receptors on the pituitary gland to maintain a homeostatic level. Its synthetic production is done through the use of biotechnology, specifically, recombinant DNA technology (See video on right). The gene that encodes human growth hormone is inserted into bacteria and the protein is produced in large quantities where it can be purified for use in humans. Synthetic production is preferable to natural production for human use as it is scalable, safer and is more consistent as the encoding gene will not undergo mutation.