Proinsulin C-peptide interferes with insulin fibril formation
| Autor: | Jan-Bernd Stukenborg, Michael Landreh, Olle Söder, Hanna Willander, Jan Johansson, Hans Jörnvall |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
chemistry.chemical_classification
Amyloid Spectrometry Mass Electrospray Ionization C-Peptide Chemistry Electrospray ionization Insulin medicine.medical_treatment Biophysics Peptide macromolecular substances Cell Biology Hydrogen-Ion Concentration Fibril Biochemistry medicine.anatomical_structure medicine Humans Hydrogen–deuterium exchange Pancreas Molecular Biology Proinsulin |
| Zdroj: | Biochemical and Biophysical Research Communications. 418:489-493 |
| ISSN: | 0006-291X |
| Popis: | Insulin aggregation can prevent rapid insulin uptake and cause localized amyloidosis in the treatment of type-1 diabetes. In this study, we investigated the effect of C-peptide, the 31-residue peptide cleaved from proinsulin, on insulin fibrillation at optimal conditions for fibrillation. This is at low pH and high concentration, when the fibrils formed are regular and extended. We report that C-peptide then modulates the insulin aggregation lag time and profoundly changes the fibril appearance, to rounded clumps of short fibrils, which, however, still are Thioflavine T-positive. Electrospray ionization mass spectrometry also indicates that C-peptide interacts with aggregating insulin and is incorporated into the aggregates. Hydrogen/deuterium exchange mass spectrometry further reveals reduced backbone accessibility in insulin aggregates formed in the presence of C-peptide. Combined, these effects are similar to those of C-peptide on islet amyloid polypeptide fibrillation and suggest that C-peptide has a general ability to interact with amyloidogenic proteins from pancreatic β-cell granules. Considering the concentrations, these peptide interactions should be relevant also during physiological secretion, and even so at special sites post-secretory or under insulin treatment conditions in vivo. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect