C-peptide
Overview
Insulin
Insulin is a hormone central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the liver and muscle....
. First preproinsulin
Preproinsulin
Preproinsulin is the primary translation product of the insulin gene. It is a peptide of 110 amino acids. Preproinsulin is a precursor processed by proteases to proinsulin by removal of the signal peptide and then to insulin by removal of the connecting peptide in order to be biologically...
is secreted with an A-chain, C-peptide, a B-chain, and a signal sequence. The signal sequence is cut off, leaving proinsulin
Proinsulin
Proinsulin is the prohormone precursor to insulin made in the beta cells of the islets of Langerhans, specialized regions of the pancreas. In humans, proinsulin is encoded by the INS gene.- Synthesis and post-translational modification :...
. Then the C-peptide is cut off, leaving the A-chain and B-chain to form insulin.
C-peptide should not be confused with c-reactive protein
C-reactive protein
C-reactive protein is a protein found in the blood, the levels of which rise in response to inflammation...
or Protein C
Protein C
Protein C, also known as autoprothrombin IIA and blood coagulation factor XIV, is a zymogenic protein, the activated form of which plays an important role in regulating blood clotting, inflammation, cell death and maintaining the permeability of blood vessel walls in humans and other animals...
.
Proinsulin C-peptide was first described in 1967 in connection with the discovery of the insulin
Insulin
Insulin is a hormone central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the liver and muscle....
biosynthesis.
