title: Identification of proinsulin and C-peptide in human serum by a specific immunoassay.
abstract: An immunoassay for the measurement of human proinsulin and C-peptide is described. By a combination of this system and an insulin immunoassay, proinsulin, insulin, and C-peptide were identified in acid-ethanol extracts of serum after gel filtration. In keeping with the results of biosynthetic studies, insulin and C-peptide were found to be present in equimolar amounts. The absolute values of serum proinsulin determined independently in the two assays corresponded closely.
mesh_terms: D007516:Adenoma, Islet Cell / Q000097:blood; D000595:Amino Acid Sequence; D000818:Animals; D000937:Antigen-Antibody Reactions; D002417:Cattle; D002850:Chromatography, Gel; D006801:Humans; D007118:Immunoassay; D007328:Insulin / Q000096:biosynthesis*; D007456:Iodine Isotopes; D008722:Methods; D009765:Obesity / Q000097:blood; D010455:Peptides / Q000097:blood*; D011817:Rabbits; D013045:Species Specificity; D013552:Swine
chemical_list: D007328:Insulin; D007456:Iodine Isotopes; D010455:Peptides