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Imaging Structurally Heterogeneous Protein Complexes in Diatoms transformed with mesoporous biosilica targeted proteins


EMSL Project ID
48780

Abstract

Our long-term goal is to monitor location and functionally-relevant structural transitions of proteins stabilized by in vivo sol-gel condensation of protein-silica composite structures. Such measurements are anticipated to permit development of predictive rules for the construction of optimal biosilica-based biomaterials, which include catalysis platforms for biofuels. The biarsenical fluorescent probes AsCy3/AsCy3e, which bind the tetracysteine tag AsCy3Tag encoded in fusion proteins, have been useful in localizing biosilica-targeted recombinant proteins in both nascent and mature biosilica of transformed diatoms. An improved tag sequence (Cy3+6Tag) that permits higher affinity and enhanced fluorescence detection at the single peptide level was recently reported, and we have extended use of this tag to detection of recombinant proteins in biosilica of transformed diatoms using epifluorescence microscopy. A better understanding of the localization of the tagged proteins in both biosilica and non-biosilica structures can be gained through high-resolution imaging of labeled cells and isolated biosilica. The specific aim of this Rapid Access proposal is to compare the original Cy3Tag and the new Cy3+6Tag in resolving localization of labeled proteins using Super Resolution Structured Illumination Microscopy (3D-SIM). The results of 3D-SIM imaging are needed to complement and strengthen existing comparisons using lower resolution imaging approaches. The findings, which are planned for immediate submission for publication and subsequent presentation at a major scientific conference and program review, would extend the recently reported proof of principle in vitro biochemical study to tagged live cells and isolated biosilica frustules.

Project Details

Project type
Limited Scope
Start Date
2015-03-16
End Date
2015-05-16
Status
Closed

Team

Principal Investigator

Guri Roesijadi
Institution
Pacific Northwest National Laboratory

Team Members

Nicole Ford
Institution
Pacific Northwest National Laboratory

Karen Hecht
Institution
Pacific Northwest National Laboratory

Thomas Squier
Institution
Western University of Health Sciences