pH-Dependent Interaction between C-Peptide and Phospholipid Bicelles
2012 (English)In: Journal of Biophysics, ISSN 1687-8019, 185907- p.Article in journal (Refereed) Published
C-peptide is the connecting peptide between the A and B chains of insulin in proinsulin. In this paper, we investigate the interaction between C-peptide and phospholipid bicelles, by circular dichroism and nuclear magnetic resonance spectroscopy, and in particular the pH dependence of this interaction. The results demonstrate that C-peptide is largely unstructured independent of pH, but that a weak structural induction towards a short stretch of β-sheet is induced at low pH, corresponding to the isoelectric point of the peptide. Furthermore, it is demonstrated that C-peptide associates with neutral phospholipid bicelles as well as acidic phospholipid bicelles at this low pH. C-peptide does not undergo a large structural rearrangement as a consequence of lipid interaction, which indicates that the folding and binding are uncoupled. In vivo, local variations in environment, including pH, may cause C-peptide to associate with lipids, which may affect the aggregation state of the peptide.
Place, publisher, year, edition, pages
2012. 185907- p.
Research subject Biophysics
IdentifiersURN: urn:nbn:se:su:diva-79050DOI: 10.1155/2012/185907OAI: oai:DiVA.org:su-79050DiVA: diva2:546703
FunderSwedish Research Council, 621-2011-5964