What is the biosynthesis of insulin?

Updated: Jan 02, 2019
  • Author: Saranya Buppajarntham, MD; Chief Editor: Eric B Staros, MD  more...
  • Print
Answer

Answer

Insulin is a peptide hormone that is secreted from beta cells of the islets of Langerhans in the pancreas. It is initially synthesized in endoplasmic reticulum and Golgi apparatus as proinsulin; it is then cleaved to insulin and C-peptide. Although insulin and C-peptide are cosecreted in equal molar proportions, the ratio of serum insulin to C-peptide is 1:5-15. Fifty to sixty percent of insulin is extracted by the liver before it reaches systemic circulation, and it has a half-life of only 4 minutes. In contrast, C-peptide and proinsulin are excreted via the kidney. [6]


Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!