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Updated: Aug 11, 2025

Imaging Calcium Dynamics in Subpopulations of Mouse Pancreatic Islet Cells
Published on: November 26, 2019
Ca2+-Responsive Glyco-insulin
Shunliang Wu1,2, Mads Østergaard2, Freja Fredholt3,4
1Biomolecular Nanoscale Engineering Center, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark.
Abstract:
Chemical modification of peptides and proteins, such as PEGylation and lipidation, creates conjugates with new properties. However, they are typically not dynamic or stimuli-responsive. Self-assembly controlled by a stimulus will allow adjusting properties directly. Here, we report that conjugates of oligogalacturonic acids (OGAs), isolated from plant-derived pectin, are Ca2+-responsive. We report the conjugation of OGA to human insulin (HI) to create new glyco-insulins. In addition, we coupled OGA to model peptides. We studied their self-assembly by dynamic light scattering, small-angle X-ray scattering, and circular dichroism, which showed that the self-assembly to form nanostructures depended on the length of the OGA sequence and Zn2+ and Ca2+ concentrations. Subcutaneous administration of OGA12-HI with Zn2+ showed a stable decrease in blood glucose over a longer period of time compared to HI, despite the lower receptor binding affinity.
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