Using molecular mechanics to predict bulk material properties of fibronectin fibers
Bradshaw, Mark J.
Cheung, Man C.
Ehrlich, Daniel J.
Smith, Michael L.
MetadataShow full item record
Citation (published version)Bradshaw MJ, Cheung MC, Ehrlich DJ, Smith ML (2012) Using Molecular Mechanics to Predict Bulk Material Properties of Fibronectin Fibers. PLoS Comput Biol 8(12): e1002845. https://doi.org/10.1371/journal.pcbi.1002845
The structural proteins of the extracellular matrix (ECM) form fibers with finely tuned mechanical properties matched to the time scales of cell traction forces. Several proteins such as fibronectin (Fn) and fibrin undergo molecular conformational changes that extend the proteins and are believed to be a major contributor to the extensibility of bulk fibers. The dynamics of these conformational changes have been thoroughly explored since the advent of single molecule force spectroscopy and molecular dynamics simulations but remarkably, these data have not been rigorously applied to the understanding of the time dependent mechanics of bulk ECM fibers. Using measurements of protein density within fibers, we have examined the influence of dynamic molecular conformational changes and the intermolecular arrangement of Fn within fibers on the bulk mechanical properties of Fn fibers. Fibers were simulated as molecular strands with architectures that promote either equal or disparate molecular loading under conditions of constant extension rate. Measurements of protein concentration within micron scale fibers using deep ultraviolet transmission microscopy allowed the simulations to be scaled appropriately for comparison to in vitro measurements of fiber mechanics as well as providing estimates of fiber porosity and water content, suggesting Fn fibers are approximately 75% solute. Comparing the properties predicted by single molecule measurements to in vitro measurements of Fn fibers showed that domain unfolding is sufficient to predict the high extensibility and nonlinear stiffness of Fn fibers with surprising accuracy, with disparately loaded fibers providing the best fit to experiment. This work shows the promise of this microstructural modeling approach for understanding Fn fiber properties, which is generally applicable to other ECM fibers, and could be further expanded to tissue scale by incorporating these simulated fibers into three dimensional network models.
RightsCopyright: © 2012 Bradshaw et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Showing items related by title, author, creator and subject.
Contribution of leaf specular reflection to canopy reflectance under black soil case using stochastic radiative transfer model Yang, Bin; Knyazikhin, Yuri; Zhao, Haimeng; Ma, Yuzhong (Elsevier Science BV, 2018-12-15)Numerous canopy radiative transfer models have been proposed based on the assumption of “ideal bi-Lambertian leaves” with the aim of simplifying the interactions between photons and vegetation canopies. This assumption may ...
Integrating archaeology and ancient DNA analysis to address invasive species colonization in the Gulf of Alaska West, Catherine; Hofman, Courtney A.; Ebbert, Steve; Martin, John; Shirazi, Sabrina; Dunning, Samantha; Maldonado, Jesus E. (WILEY, 2017-10-01)The intentional and unintentional movement of plants and animals by humans has transformed ecosystems and landscapes globally. Assessing when and how a species was introduced are central to managing these transformed ...
Inconsistencies of interannual variability and trends in long-term satellite leaf area index products Jiang, Chongya; Ryu, Youngryel; Fang, Hongliang; Myneni, Ranga; Claverie, Martin; Zhu, Zaichun (2017-07-06)Understanding the long-term performance of global satellite leaf area index (LAI) products is important for global change research. However, few effort has been devoted to evaluating the long-term time-series consistencies ...