Macromolecular crowding significantly influences protein folding, stability, and aggregation within cellular environments. Here, Cellular Retinoic Acid Binding Protein I (CRABP I), a highly stable β-barrel protein with low intrinsic aggregation propensity, was employed to investigate the concentration-dependent effects of PEG 1000 on temperature-assisted refolding. Structural, functional, and biological consequences of refolding were examined using spectroscopic, microscopic, rheological, ligand-binding, zeta potential, and in vivo analyses. Refolding in the absence of PEG produced soluble but structurally heterogeneous intermediates. In contrast, low PEG concentration promoted intermolecular protein-protein interactions, leading to amorphous aggregation, altered structural properties, reduced retinoic acid-binding activity, and enhanced oxidative stress and cellular damage in Drosophila melanogaster. Higher PEG concentrations suppressed aggregation and favoured structurally stabilized conformations with preserved ligand-binding function. These findings demonstrate that PEG 1000 acts as a concentration-dependent molecular switch governing the balance between aggregation and productive refolding of CRABP I.
Laxmipriya Prusty, Kalpanarani Dash, Monalisa Mishra et al.· International Journal of Bio...· 0 citations
Designing multifunctional nanocarriers that integrate controlled drug delivery, favorable protein interactions, and accelerated tissue repair remains a key challenge in nanomedicine. In this study, we have engineered a magnetically responsive, biocompatible Fe3O4@SiO2 nanoparticle functionalized with a bromocholine-based ionic liquid. This surface design enabled efficient encapsulation and sustained release of the hydrophobic anticancer drug quercetin over 72 h under physiological conditions. Given the critical role of plasma protein adsorption in determining nanomaterial fate, systematic interaction studies with human serum albumin (HSA) were investigated using spectroscopic analyses, molecular docking, and esterase-like activity assays. The results showed that the nanocarriers exhibited stable protein binding with minimal conformational perturbation and preserved enzymatic activity, indicating excellent biocompatibility. Further, in an in vivo wound healing model, topical application of quercetin-loaded nanocarriers at 500 ppm led to rapid wound closure, with significant wound reduction observed within 3 h. The magnetic core further offers potential for external guidance to wound sites. Overall, this bromocholine-functionalized platform combines tunable drug release, biointerfacial compatibility, and rapid healing efficacy, making it a promising candidate for advanced wound therapy.
