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Revealing the assembly of filamentous proteins with scanning transmission electron microscopy
Filamentous proteins are responsible for the superior mechanical strength of our cells and tissues. The remarkable mechanical properties of protein filaments are tied to their complex molecular packing structure. However, since these filaments have widths of several to tens of nanometers, it has rem...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6924676/ https://www.ncbi.nlm.nih.gov/pubmed/31860683 http://dx.doi.org/10.1371/journal.pone.0226277 |
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author | Martinez-Torres, Cristina Burla, Federica Alkemade, Celine Koenderink, Gijsje H. |
author_facet | Martinez-Torres, Cristina Burla, Federica Alkemade, Celine Koenderink, Gijsje H. |
author_sort | Martinez-Torres, Cristina |
collection | PubMed |
description | Filamentous proteins are responsible for the superior mechanical strength of our cells and tissues. The remarkable mechanical properties of protein filaments are tied to their complex molecular packing structure. However, since these filaments have widths of several to tens of nanometers, it has remained challenging to quantitatively probe their molecular mass density and three-dimensional packing order. Scanning transmission electron microscopy (STEM) is a powerful tool to perform simultaneous mass and morphology measurements on filamentous proteins at high resolution, but its applicability has been greatly limited by the lack of automated image processing methods. Here, we demonstrate a semi-automated tracking algorithm that is capable of analyzing the molecular packing density of intra- and extracellular protein filaments over a broad mass range from STEM images. We prove the wide applicability of the technique by analyzing the mass densities of two cytoskeletal proteins (actin and microtubules) and of the main protein in the extracellular matrix, collagen. The high-throughput and spatial resolution of our approach allow us to quantify the internal packing of these filaments and their polymorphism by correlating mass and morphology information. Moreover, we are able to identify periodic mass variations in collagen fibrils that reveal details of their axially ordered longitudinal self-assembly. STEM-based mass mapping coupled with our tracking algorithm is therefore a powerful technique in the characterization of a wide range of biological and synthetic filaments. |
format | Online Article Text |
id | pubmed-6924676 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-69246762020-01-07 Revealing the assembly of filamentous proteins with scanning transmission electron microscopy Martinez-Torres, Cristina Burla, Federica Alkemade, Celine Koenderink, Gijsje H. PLoS One Research Article Filamentous proteins are responsible for the superior mechanical strength of our cells and tissues. The remarkable mechanical properties of protein filaments are tied to their complex molecular packing structure. However, since these filaments have widths of several to tens of nanometers, it has remained challenging to quantitatively probe their molecular mass density and three-dimensional packing order. Scanning transmission electron microscopy (STEM) is a powerful tool to perform simultaneous mass and morphology measurements on filamentous proteins at high resolution, but its applicability has been greatly limited by the lack of automated image processing methods. Here, we demonstrate a semi-automated tracking algorithm that is capable of analyzing the molecular packing density of intra- and extracellular protein filaments over a broad mass range from STEM images. We prove the wide applicability of the technique by analyzing the mass densities of two cytoskeletal proteins (actin and microtubules) and of the main protein in the extracellular matrix, collagen. The high-throughput and spatial resolution of our approach allow us to quantify the internal packing of these filaments and their polymorphism by correlating mass and morphology information. Moreover, we are able to identify periodic mass variations in collagen fibrils that reveal details of their axially ordered longitudinal self-assembly. STEM-based mass mapping coupled with our tracking algorithm is therefore a powerful technique in the characterization of a wide range of biological and synthetic filaments. Public Library of Science 2019-12-20 /pmc/articles/PMC6924676/ /pubmed/31860683 http://dx.doi.org/10.1371/journal.pone.0226277 Text en © 2019 Martinez-Torres et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
spellingShingle | Research Article Martinez-Torres, Cristina Burla, Federica Alkemade, Celine Koenderink, Gijsje H. Revealing the assembly of filamentous proteins with scanning transmission electron microscopy |
title | Revealing the assembly of filamentous proteins with scanning transmission electron microscopy |
title_full | Revealing the assembly of filamentous proteins with scanning transmission electron microscopy |
title_fullStr | Revealing the assembly of filamentous proteins with scanning transmission electron microscopy |
title_full_unstemmed | Revealing the assembly of filamentous proteins with scanning transmission electron microscopy |
title_short | Revealing the assembly of filamentous proteins with scanning transmission electron microscopy |
title_sort | revealing the assembly of filamentous proteins with scanning transmission electron microscopy |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6924676/ https://www.ncbi.nlm.nih.gov/pubmed/31860683 http://dx.doi.org/10.1371/journal.pone.0226277 |
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