Optimizing the Design of Diatom Biosilica-Targeted Fusion Proteins in Biosensor Construction for <i>Bacillus anthracis</i> Detection

In vivo functionalization of diatom biosilica frustules by genetic manipulation requires careful consideration of the overall structure and function of complex fusion proteins. Although we previously had transformed <i>Thalassiosira pseudonana</i> with constructs containing a single doma...

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Main Authors: Nicole R. Ford, Yijia Xiong, Karen A. Hecht, Thomas C. Squier, Gregory L. Rorrer, Guritno Roesijadi
Format: Article
Language:English
Published: MDPI AG 2020-01-01
Series:Biology
Subjects:
Online Access:https://www.mdpi.com/2079-7737/9/1/14
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author Nicole R. Ford
Yijia Xiong
Karen A. Hecht
Thomas C. Squier
Gregory L. Rorrer
Guritno Roesijadi
author_facet Nicole R. Ford
Yijia Xiong
Karen A. Hecht
Thomas C. Squier
Gregory L. Rorrer
Guritno Roesijadi
author_sort Nicole R. Ford
collection DOAJ
description In vivo functionalization of diatom biosilica frustules by genetic manipulation requires careful consideration of the overall structure and function of complex fusion proteins. Although we previously had transformed <i>Thalassiosira pseudonana</i> with constructs containing a single domain antibody (sdAb) raised against the <i>Bacillus anthracis</i> Sterne strain, which detected an epitope of the surface layer protein EA1 accessible in lysed spores, we initially were unsuccessful with constructs encoding a similar sdAb that detected an epitope of EA1 accessible in intact spores and vegetative cells. This discrepancy limited the usefulness of the system as an environmental biosensor for <i>B. anthracis</i>. We surmised that to create functional biosilica-localized biosensors with certain constructs, the biosilica targeting and protein trafficking functions of the biosilica-targeting peptide Sil3<sub>T8</sub> had to be uncoupled. We found that retaining the ER trafficking sequence at the N-terminus and relocating the Sil3<sub>T8</sub> targeting peptide to the C-terminus of the fusion protein resulted in successful detection of EA1 with both sdAbs. Homology modeling of antigen binding by the two sdAbs supported the hypothesis that the rescue of antigen binding in the previously dysfunctional sdAb was due to removal of steric hindrances between the antigen binding loops and the diatom biosilica for that particular sdAb.
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spelling doaj.art-3d52fe080c394166ad55c2ed6d1bb1302023-09-02T06:06:35ZengMDPI AGBiology2079-77372020-01-01911410.3390/biology9010014biology9010014Optimizing the Design of Diatom Biosilica-Targeted Fusion Proteins in Biosensor Construction for <i>Bacillus anthracis</i> DetectionNicole R. Ford0Yijia Xiong1Karen A. Hecht2Thomas C. Squier3Gregory L. Rorrer4Guritno Roesijadi5Marine Biotechnology Group, Pacific Northwest National Laboratory, Sequim, WA 98382, USADepartment of Basic Medical Sciences, Western University of Health Sciences, Lebanon, OR 97355, USAMarine Biotechnology Group, Pacific Northwest National Laboratory, Sequim, WA 98382, USADepartment of Basic Medical Sciences, Western University of Health Sciences, Lebanon, OR 97355, USASchool of Chemical Biological and Environmental Engineering, Oregon State University, Corvallis, OR 97331, USAMarine Biotechnology Group, Pacific Northwest National Laboratory, Sequim, WA 98382, USAIn vivo functionalization of diatom biosilica frustules by genetic manipulation requires careful consideration of the overall structure and function of complex fusion proteins. Although we previously had transformed <i>Thalassiosira pseudonana</i> with constructs containing a single domain antibody (sdAb) raised against the <i>Bacillus anthracis</i> Sterne strain, which detected an epitope of the surface layer protein EA1 accessible in lysed spores, we initially were unsuccessful with constructs encoding a similar sdAb that detected an epitope of EA1 accessible in intact spores and vegetative cells. This discrepancy limited the usefulness of the system as an environmental biosensor for <i>B. anthracis</i>. We surmised that to create functional biosilica-localized biosensors with certain constructs, the biosilica targeting and protein trafficking functions of the biosilica-targeting peptide Sil3<sub>T8</sub> had to be uncoupled. We found that retaining the ER trafficking sequence at the N-terminus and relocating the Sil3<sub>T8</sub> targeting peptide to the C-terminus of the fusion protein resulted in successful detection of EA1 with both sdAbs. Homology modeling of antigen binding by the two sdAbs supported the hypothesis that the rescue of antigen binding in the previously dysfunctional sdAb was due to removal of steric hindrances between the antigen binding loops and the diatom biosilica for that particular sdAb.https://www.mdpi.com/2079-7737/9/1/14diatombiosilicabiosensoranthraxbiotechnologymolecular biology
spellingShingle Nicole R. Ford
Yijia Xiong
Karen A. Hecht
Thomas C. Squier
Gregory L. Rorrer
Guritno Roesijadi
Optimizing the Design of Diatom Biosilica-Targeted Fusion Proteins in Biosensor Construction for <i>Bacillus anthracis</i> Detection
Biology
diatom
biosilica
biosensor
anthrax
biotechnology
molecular biology
title Optimizing the Design of Diatom Biosilica-Targeted Fusion Proteins in Biosensor Construction for <i>Bacillus anthracis</i> Detection
title_full Optimizing the Design of Diatom Biosilica-Targeted Fusion Proteins in Biosensor Construction for <i>Bacillus anthracis</i> Detection
title_fullStr Optimizing the Design of Diatom Biosilica-Targeted Fusion Proteins in Biosensor Construction for <i>Bacillus anthracis</i> Detection
title_full_unstemmed Optimizing the Design of Diatom Biosilica-Targeted Fusion Proteins in Biosensor Construction for <i>Bacillus anthracis</i> Detection
title_short Optimizing the Design of Diatom Biosilica-Targeted Fusion Proteins in Biosensor Construction for <i>Bacillus anthracis</i> Detection
title_sort optimizing the design of diatom biosilica targeted fusion proteins in biosensor construction for i bacillus anthracis i detection
topic diatom
biosilica
biosensor
anthrax
biotechnology
molecular biology
url https://www.mdpi.com/2079-7737/9/1/14
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