Oligomerization and insulin interactions of proinsulin C-peptide: Threefold relationships to properties of insulin
2010 (English)In: Biochemical and Biophysical Research Communications - BBRC, ISSN 0006-291X, E-ISSN 1090-2104, Vol. 391, no 3, 1561-1566 p.Article in journal (Refereed) Published
Three principally different sites of action have been reported for proinsulin C-peptide, at surface-mediated, intracellular, and extracellular locations. Following up on the latter, we now find that (i) mass spectrometric analyses reveal the presence of the C-peptide monomer in apparent equilibrium with a low-yield set of oligomers in weakly acidic or basic aqueous solutions, even at low peptide concentrations (sub-mu M). It further shows not only C-peptide to interact with insulin oligomers (known before), but also the other way around. (ii) Polyacrylamide gel electrophoresis of C-peptide shows detectable oligomers upon Western blotting. Formation of thioflavin T positive material was also detected. (iii) Cleavage patterns of analogues are compatible with C-peptide as a substrate of insulin degrading enzyme. Combined, the results demonstrate three links with insulin properties, in a manner reminiscent of amyloidogenic peptides and their chaperons in other systems. If so, peripheral C-peptide/insulin interactions, absolute amounts of both peptides and their ratios may be relevant to consider in diabetic and associated diseases.
Place, publisher, year, edition, pages
2010. Vol. 391, no 3, 1561-1566 p.
Proinsulin C-peptide, Insulin degrading enzyme, Oligomerization, Mass spectrometry, Diabetes types 1 and 2, Peptide deposits
IdentifiersURN: urn:nbn:se:su:diva-50314DOI: 10.1016/j.bbrc.2009.12.125ISI: 000274097800048OAI: oai:DiVA.org:su-50314DiVA: diva2:380772
authorCount :102010-12-222010-12-222010-12-22Bibliographically approved