Description
Principle of the assay: This assay employs the competitive enzyme immunoassay technique. The microtiter plate provided in this kit has been pre-coated with goat-anti-rabbit antibody. Standards or samples are added to the appropriate microtiter plate wells with an antibody specific for CP and Horseradish Peroxidase (HRP) conjugated CP. The competitive inhibition reaction is launched between with HRP labeled CP and unlabeled CP with the antibody. A substrate solution is added to the wells and the color develops in opposite to the amount of CP in the sample. The color development is stopped and the intensity of the color is measured.
Background: The connecting peptide, or C-peptide, is a short 31-amino-acid protein that connects insulin's A-chain to its B-chain in the proinsulin molecule. In the insulin synthesis pathway, first preproinsulin is translocated into the endoplasmic reticulum of beta cells of the pancreas with an A-chain, a C-peptide, a B-chain, and a 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, the C-peptide is removed, leaving the A-chain and B-chain, bound together by disulfide bonds, that constitute the insulin molecule