Insulin

Name:
Insulin
Detailed information:
A polypeptide hormone having a molecular weight of 5733. It is formed in the isles of Langerhans located in the pancreas and was so named for this reason. Insulin is composed of 16 amino acids arranged in a coiled chain and cross-linked in several places by the disulfide bonds of cystine residues. The sequence of amino acids has been elucidated. The insulin molecule was synthesized in 1963. In 1977, rat insulin was produced in the bacterium E. coli by recombinant DNA techniques. A year later human insulin was generated after chemically synthesized genes were added to E. coli. This synthetic insulin is now in commercial production and has been approved by FDA. Insulin regulates carbohydrate metabolism in the body by decreasing the blood glucose level. A systemic deficiency leads to diabetes.

Properties:

White powder or hexagonal crystals. Readily soluble in dilute acids; soluble in water.

Derivation:

Extraction of minced pancreas with acidified dilute alcohol, followed by precipitation with absolute alcohol; also by gene-splicing methods.

Grade:

USP, in various solutions or suspensions that include insulin injection; isophane insulin suspension; protamine zinc insulin suspension; NF, as globin zinc insulin injection.

Hazard:

Overdosage can be fatal.

Use:

Medicine (for diabetes control).

See Banting; recombinant DNA.