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Updated: Aug 24, 2025

Characterizing Individual Protein Aggregates by Infrared Nanospectroscopy and Atomic Force Microscopy
Published on: September 12, 2019
Nano-assemblies enhance chaperone activity, stability, and delivery of alpha B-crystallin-D3 (αB-D3)
Arun K Upadhyay1, Niklaus H Mueller2, J Mark Petrash2
1Nanomedicine and Drug Delivery Laboratory, Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
Abstract:
Crystallins, small heat shock chaperone proteins that prevent protein aggregation, are of potential value in treating protein aggregation disorders. However, their therapeutic use is limited by their low potency and poor intracellular delivery. One approach to facilitate the development of crystallins is to improve their activity, stability, and delivery. In this study, zinc addition to αB-crystallin-D3 (αB-D3) formed supramolecular nano- and micro- assemblies, induced dose-dependent changes in structure (beta-sheet to alpha-helix) and increased surface hydrophobicity and chemical stability. Further, crystallin assemblies exhibited a size-dependent chaperone activity, with the nano-assemblies being superior to micro-assemblies and 4.3-fold more effective than the native protein in preventing β-mercaptoethanol induced aggregation of insulin. Insulin rescued by crystallin assemblies retained the activity as evidenced by glucose uptake in 3T3-L1 cells. The most active nano-assemblies enhanced protein stability, in the presence of urea, by 1.6-fold, whereas intracellular delivery was enhanced by 3.0-fold. The αB-D3 crystallin nano-assemblies exhibit uniquely enhanced stability, activity, and delivery compared to the native protein.
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