C-peptide

Also known as INS(57-87), insulin(57-87), human C-peptide

The connecting peptide, or C-peptide, is a short 31-amino-acid polypeptide that connects insulin's A-chain to its B-chain in the proinsulin molecule. In the context of diabetes or hypoglycemia, a measurement of C-peptide blood serum levels can be used to distinguish between different conditions with similar clinical features.

Chemical data

Formula: C112H179N35O46
Molecular weight: 2751.8 g/mol
IUPAC name: (4S)-4-amino-5-[[2-[[(2S)-1-[[(2S)-1-[[2-[[(2S)-5-amino-1-[[(2S)-1-[[2-[[(2S)-5-amino-1-[[2-[[(2S)-1-[[(2S)-1-[[2-[[2-[[2-[(2S)-2-[[2-[[(2S)-1-[[2-[[2-[[(2S)-1-[[(2S)-5-amino-1-[[2-[[(2S)-1-[[(2S)-1-[[(2S)-1-[[(2S)-1-[[2-[[2-[[2-[[(1S)-4-amino-1-carboxy-4-oxobutyl]amino]-2-oxoethyl]amino]-2-oxoethyl]amino]-2-oxoethyl]amino]-4-carboxy-1-oxobutan-2-yl]amino]-4-methyl-1-oxopentan-2-yl]amino]-1-oxopropan-2-yl]amino]-4-methyl-1-oxopentan-2-yl]amino]-2-oxoethyl]amino]-1,5-dioxopentan-2-yl]amino]-4-methyl-1-oxopentan-2-yl]amino]-2-oxoethyl]amino]-2-oxoethyl]amino]-1-oxopropan-2-yl]amino]-2-oxoethyl]carbamoyl]pyrrolidin-1-yl]-2-oxoethyl]amino]-2-oxoethyl]amino]-2-oxoethyl]amino]-4-methyl-1-oxopentan-2-yl]amino]-4-carboxy-1-oxobutan-2-yl]amino]-2-oxoethyl]amino]-1,5-dioxopentan-2-yl]amino]-2-oxoethyl]amino]-3-methyl-1-oxobutan-2-yl]amino]-1,5-dioxopentan-2-yl]amino]-2-oxoethyl]amino]-3-carboxy-1-oxopropan-2-yl]amino]-4-carboxy-1-oxobutan-2-yl]amino]-2-oxoethyl]amino]-5-oxopentanoic acid
SMILES: C[C@@H](C(=O)NCC(=O)NCC(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CCC(=O)N)C(=O)NCC(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](C)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CCC(=O)O)C(=O)NCC(=O)NCC(=O)NCC(=O)N[C@@H](CCC(=O)N)C(=O)O)NC(=O)CNC(=O)[C@@H]1CCCN1C(=O)CNC(=O)CNC(=O)CNC(=O)[C@H](CC(C)C)NC(=O)[C@H](CCC(=O)O)NC(=O)CNC(=O)[C@H](CCC(=O)N)NC(=O)CNC(=O)[C@H](C(C)C)NC(=O)[C@H](CCC(=O)N)NC(=O)CNC(=O)[C@H](CC(=O)O)NC(=O)[C@H](CCC(=O)O)NC(=O)CNC(=O)[C@H](CCC(=O)O)N
InChIKey: XTUNIGNWBZZIPT-NTMYLOQBSA-N
XLogP: -17.2
Polar surface area: 1290 Å²
H-bond donors: 40
H-bond acceptors: 47
Formal charge: 0

via PubChem

Research

18,448 papers

C-peptide.Diabetes care · 1982
C-peptide and diabetic kidney disease.Journal of internal medicine · 2017
C-peptide makes a comeback.Diabetes/metabolism research and reviews · 2003
C-peptide: new findings and therapeutic possibilities.Diabetes research and clinical practice · 2015
The C-peptide signaling.Experimental diabesity research · 2004

via PubMed

Wikidata facts

Mass: 2751.277698

Show 4 more facts

exact match: www.uniprot.org/uniprot/P01308#PRO_0000015820
canonical SMILES: CC(C)CC(C(=O)NC(C)C(=O)NC(CC(C)C)C(=O)NC(CCC(=O)O)C(=O)NCC(=O)NCC(=O)NCC(=O)NC(CCC(=O)N)C(=O)O)NC(=O)CNC(=O)C(CCC(=O)N)NC(=O)C(CC(C)C)NC(=O)CNC(=O)CNC(=O)C(C)NC(=O)CNC(=O)C1CCCN1C(=O)CNC(=O)CNC(=O)CNC(=O)C(CC(C)C)NC(=O)C(CCC(=O)O)NC(=O)CNC(=O)C(CCC(=O)N)NC(=O)CNC(=O)C(C(C)C)NC(=O)C(CCC(=O)N)NC(=O)CNC(=O)C(CC(=O)O)NC(=O)C(CCC(=O)O)NC(=O)CNC(=O)C(CCC(=O)O)N
chemical formula: C₁₁₂H₁₇₉N₃₅O₄₆
Commons category: C-peptide

Sources (2)

via Wikidata · CC0

~7 min read

Article

7 sections

Contents

History
Function
Cellular effects of C-peptide
Clinical uses of C-peptide testing
Therapeutics
References
External links

In the insulin synthesis pathway, first preproinsulin is translocated into the endoplasmic reticulum of beta cells of the pancreas as one polypeptide comprising the regions of the A-chain, C-peptide, B-chain, and signal sequence. The signal sequence is cleaved from the N-terminus of the peptide by a signal peptidase, leaving proinsulin. After proinsulin is packaged into vesicles in the Golgi apparatus (beta-granules), the C-peptide is removed, leaving the A-chain and B-chain bound together by disulfide bonds, that constitute the insulin molecule.