کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1932548 | 1050584 | 2010 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Oligomerization and insulin interactions of proinsulin C-peptide: Threefold relationships to properties of insulin Oligomerization and insulin interactions of proinsulin C-peptide: Threefold relationships to properties of insulin](/preview/png/1932548.png)
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-μM). 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.
Journal: Biochemical and Biophysical Research Communications - Volume 391, Issue 3, 15 January 2010, Pages 1561–1566