Open AccessGlutathione-S-transferase Fusion Protein Nanosensor
Author(s) -
R. T. Williams,
Jackson D. Harvey,
Januka Budhathoki-Uprety,
Daniel A. Heller
Publication year - 2020
Publication title -
nano letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.853
H-Index - 488
eISSN - 1530-6992
pISSN - 1530-6984
DOI - 10.1021/acs.nanolett.0c02691
Subject(s) - nanosensor , glutathione , fusion protein , carbon nanotube , glutathione s transferase , biophysics , nanotube , biosensor , nanotechnology , green fluorescent protein , chemistry , fusion , materials science , biochemistry , biology , gene , enzyme , recombinant dna , linguistics , philosophy
Fusion protein tags are widely used to capture and track proteins in research and industrial bioreactor processes. Quantifying fusion-tagged proteins normally requires several purification steps coupled with classical protein assays. Here, we developed a broadly applicable nanosensor platform that quantifies glutathione-S-transferase (GST) fusion proteins in real-time. We synthesized a glutathione-DNA-carbon nanotube system to investigate glutathione-GST interactions via semiconducting single-walled carbon nanotube (SWCNT) photoluminescence. We found that SWCNT fluorescence wavelength and intensity modulation occurred specifically in response to GST and GST-fusions. The sensor response was dependent on SWCNT structure, wherein mod ( n - m , 3) = 1 nanotube wavelength and intensity responses correlated with nanotube diameter distinctly from mod ( n - m , 3) = 2 SWCNT responses. We also found broad functionality of this sensor to diverse GST-tagged proteins. This work comprises the first label-free optical sensor for GST and has implications for the assessment of protein expression in situ, including in imaging and industrial bioreactor settings.