abnormal circulating protein level abnormal circulating C-peptide level 2023-11-13T16:45:27Z C-peptide provides a means to promote the efficient folding and assembly of the A and B chains of proinsulin in the endoplasmic reticulum during insulin biosynthesis; after cleavage of proinsulin, C-peptide is stored with insulin in the soluble phase of the secretory granules and is subsequently released in equimolar amounts with insulin, providing an independent indicator of insulin secretion. MPheno.ontology MP:0031512 abnormal circulating connecting peptide level abnormal serum C-peptide level anomaly in the amount in the blood of the connecting (C) peptide that links the A and B chains in proinsulin abnormal blood C-peptide level abnormal plasma C-peptide level