Kanda Borgognoni
Speaker's Institution
Colorado State University
4:00 PM
Virtual Research Seminar
Mixer Time
Mixer Time
Calendar (ICS) Event
Additional Information

Biological microscopic studies, once revolutionized by the discovery of clonable fluorophores like Green Fluorescent Protein (GFP), engender foundational evidence for cellular processes via in situ protein labeling and tracking by fluorescence. As light microscopy is inherently diffraction limited, electron microscopy (EM) unveils details of cellular ultrastructure with nanometer scale resolution. The primary challenge of biological EM is generating target specific contrast. While methods have been developed to create targeted contrast, none have achieved the specificity of an encodable label. We developed a clonable nanoparticle by isolating a metalloid reductase from a selenophilic plant capable of reducing selenooxyanion precursors into zero valent, amorphous Se nanoparticles (SeNPs). After demonstrating the portability of the enzyme across species through the maintenance of its activity in vitro and in vivo, modification of the wild type further enhanced its performance as a clonable selenium nanoparticle (cSeNP) tag. We then used the recombinant enzyme in a proof of concept study that involved tracking filamenting protein FtsZ in vivo. Once we expressed the cSeNP-FtsZ chimera in E. coli, electron micrographs mimicked fluorescence images from studies of GFP-FtsZ fusions. In addition, we explored the possibilities of using the enzyme to synthesize metal selenide quantum dots (QDs). We have used both a bottom-up and a top-down approach to synthesize QDs in vitro, and we continue to develop the protocols for in vivo correlative labeling applications. We continue to optimize established preservation and imaging methods to be compatible with clonable nanoparticle technology and to discover other reductases from our library of candidate species.




CSU Ram logo 2
CSU Ram logo 2