Scientific Background | This is the porcine form of proinsulin C-peptide, the connecting segment released when proinsulin is cleaved to insulin, supplied here as residues 31 to 63 of the porcine precursor. The differing residue numbering relative to the human product reflects differences in the precursor sequences rather than a different part of the molecule. C-peptide sequences diverge considerably more between species than insulin does, and that divergence is the practical reason to hold the porcine peptide separately. Immunoassays raised against human C-peptide may under-report or fail to detect the porcine sequence, so quantification in porcine samples requires a species-matched standard. Porcine material is also of historical importance, since porcine insulin preparations were a mainstay of diabetes treatment before recombinant human insulin, and C-peptide measurement features in work on islet and pancreatic tissue from pigs, including xenotransplantation research where pig islets are the graft. For studies of C-peptide's proposed biological activities, on Na+,K+-ATPase, nitric oxide and microvascular flow, most published work used the human peptide, so results obtained with the porcine sequence should not be assumed equivalent. The human variant is offered as LT2108. |
References | 1. Wahren J, Ekberg K, Johansson J, et al. Role of C-peptide in human physiology. American Journal of Physiology (2000) 278:E759. Am J Physiol 2000;278:E759 2. Physiological effects and therapeutic potential of proinsulin C-peptide. American Journal of Physiology (2014). Am J Physiol 2014 3. C-peptide: new findings and therapeutic implications in diabetes. Clinical Physiology and Functional Imaging (2004). Clin Physiol Funct Imaging 2004 |
