Journal: Scientific Reports
Article Title: Electric-field induced modulation of amorphous protein aggregates: polarization, deformation, and reorientation
doi: 10.1038/s41598-022-06995-x
Figure Lengend Snippet: ( a ) Schematic illustration of the formation of amorphous protein aggregates: four disulfide bridges (red bars) stabilize the native conformation of the lysozyme molecule (polypeptide backbone shown as blue line). Upon addition of the reducing agent DTT, these bonds break and the protein unfolds, attaining a collapsed misfolded, random coil-like conformation. The reduced proteins largely assemble into mesoscopic, flexible amorphous structures (blue conglomerate). The response of these aggregates to electric fields is explored in the present work. ( b ) The sample solution is filled into an in-situ electric-field optical cell. The cell is composed of two separated ITO glasses, which are connected to a function generator. It can be mounted onto an inverted optical microscope (as schematically shown) or onto a dynamic light scattering set-up (cf. Fig. ). The z -plane, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$z_\text {ROI}$$\end{document} z ROI , (indicated by the red line) is the region of interest and taken slightly above the bottom ITO plate. ( c ) Optical morphologies of protein aggregates (PAs) in the absence of an electric field taken a long time \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$t_\text {w}$$\end{document} t w after sample preparation, such that most reduced protein monomers have been integrated into the aggregates. The samples differ in their total protein concentrations c and hence also in their typical aggregate size. Movies of the three systems (MOVIE , , ) exposed to electric fields are provided as supplementary information.
Article Snippet: The sample is mounted on an inverted polarized optical microscope (Carl Zeiss, Axiovert 40CFL model).
Techniques: In Situ, Microscopy, Sample Prep
![( a ) Schematic illustration of the formation of amorphous protein aggregates: four disulfide bridges (red bars) stabilize the native conformation of the lysozyme molecule (polypeptide backbone shown as blue line). Upon addition of the reducing agent DTT, these bonds break and the protein unfolds, attaining a collapsed misfolded, random coil-like conformation. The reduced proteins largely assemble into mesoscopic, flexible amorphous structures (blue conglomerate). The response of these aggregates to electric fields is explored in the present work. ( b ) The sample solution is filled into an in-situ electric-field optical cell. The cell is composed of two separated ITO glasses, which are connected to a function generator. It can be mounted onto an inverted optical <t>microscope</t> (as schematically shown) or onto a dynamic light scattering set-up (cf. Fig. ). The z -plane, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$z_\text {ROI}$$\end{document} z ROI , (indicated by the red line) is the region of interest and taken slightly above the bottom ITO plate. ( c ) Optical morphologies of protein aggregates (PAs) in the absence of an electric field taken a long time \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$t_\text {w}$$\end{document} t w after sample preparation, such that most reduced protein monomers have been integrated into the aggregates. The samples differ in their total protein concentrations c and hence also in their typical aggregate size. Movies of the three systems (MOVIE , , ) exposed to electric fields are provided as supplementary information.](https://pub-med-central-images-cdn.bioz.com/pub_med_central_ids_ending_with_6516/pmc08866516/pmc08866516__41598_2022_6995_Fig1_HTML.jpg)