Reaction: Carboxypeptidase E hydrolyzes Insulin(57-89) to yield C-peptide (Insulin(57-87))
- in pathway: Insulin processing
The exopeptidase Carboxypeptidase E (CPE, also called Carboxypeptidase H) successively cleaves the C terminal arginine 89 and lysine 88 from insulin(57-89) to yield C peptide, which is released in equimolar amounts with mature insulin by vesicle exocytosis. The biochemical details of this reaction have been worked out for the rat protein (Davidson & Hutton 1987) and studies of variant forms of the human protein suggest the same function for human CPE Chen et al. 2001). The reaction occurs in immature secretory granules (Orci et al. 1985).
Reaction - small molecule participants:
L-Lys [secretory granule lumen]
L-Arg [secretory granule lumen]
H2O [secretory granule lumen]
Reactome.org reaction link: R-HSA-9023159
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Reaction input - small molecules:
water
Reaction output - small molecules:
L-lysinium(1+)
L-argininium(1+)
Reactome.org link: R-HSA-9023159