PeptideHormone

Insulin

The anabolic master switch for glucose uptake and storage.

EndogenousEstablished

Identity

Class
Two-chain peptide hormone (51 aa, A+B chains)
Source
Pancreatic islet beta cells
Receptor
Insulin receptor (a receptor tyrosine kinase)

Key properties

Molecular weight
~5,807.6 Da
Half-life (native)
~4–6 min
Model dosing

Approximate values for the native hormone. Engineered analogs are often deliberately larger and far longer-acting.

Mechanism

Secreted in response to rising glucose, insulin binds its receptor tyrosine kinase to drive glucose uptake in muscle and fat (via GLUT4) and storage as glycogen and lipid. It is the dominant anabolic signal of the fed state.

Reference notes

  • Insulin's receptor is a tyrosine kinase, unlike the GPCRs used by most peptide hormones here.
  • The incretins act upstream — they amplify glucose-stimulated insulin secretion rather than replacing insulin.
  • It was the first peptide hormone sequenced and the first produced by recombinant DNA.

Selected literature

Curated peer-reviewed reviews, sourced from PubMed. Selected for relevance, not exhaustive — open any entry on PubMed for the full record and its primary citations.

  1. 1.100 years of insulin: celebrating the past, present and future of diabetes therapy · Nature medicine, 2021 · PMID 34267380
  2. 2.Insulin: The master regulator of glucose metabolism · Metabolism: clinical and experimental, 2022 · PMID 35066003