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Integrin, as a mechanotransducer, establishes the mechanical reciprocity between the extracellular matrix (ECM) and cells at integrin-mediated adhesion sites. This study used steered molecular dynamics (SMD) simulations to investigate the mechanical responses of integrinαvβ3with and without 10th type III fibronectin (FnIII10) binding for tensile, bending and torsional loading conditions. The ligand-binding integrin confirmed the integrin activation during equilibration and altered the integrin dynamics by changing the interface interaction between β-tail, hybrid and epidermal growth factor domains during initial tensile loading. The tensile deformation in integrin molecules indicated that fibronectin ligand binding modulates its mechanical responses in the folded and unfolded conformation states. The bending deformation responses of extended integrin models reveal the change in behaviour of integrin molecules in the presence of Mn2+ion and ligand based on the application of force in the folding and unfolding directions of integrin. Furthermore, these SMD simulation results were used to predict the mechanical properties of integrin underlying the mechanism of integrin-based adhesion. The evaluation of integrin mechanics provides new insights into understanding the mechanotransmission (force transmission) between cells and ECM and contributes to developing an accurate model for integrin-mediated adhesion. This article is part of a discussion meeting issue ‘Supercomputing simulations of advanced materials’.
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Machine Learning Classification of Integrin-Expression-Based Magnetic Sorted SW 620 Cells by Simultaneous O-PTIR and SERS
Immortalized cell lines are commonly used for in vitro studies such as drug efficacy, toxicology, and life-cycle due to their cost effectiveness and accessibility; however, subpopulations within a cell line can arise from random mutations or asynchronous cell cycles which may lead to results that make interpretation difficult. A method that could classify these differences and separate unique subpopulations would increase understanding of heterogeneous cellular responses. In the present work, we explore spectroscopic signals associated with subpopulations of cells magnetically sorted on the basis of α5β1 integrin binding to cyclic-RGDfC which mimics fibronectin in the extracellular matrix. SW620 colon cancer cells were incubated with cyclic-RGDfC functionalized gold-coated, iron core nanoparticles and magnetically sorted. The subpopulations from the sort were imaged (N=10 positive and N=10 negative, number of cells) via simultaneous surface-enhanced Raman scattering (SERS) and optical-photothermal infrared spectroscopy (O-PTIR). Pearson correlations of the standard peptide-protein interaction in the SERS channel allowed for visualization of the cyclic RGDfC – integrin α5β1 interaction. Partial least squares discriminant analysis of the O-PTIR spectra collected from cell maps successfully classified the positively or negatively sorted cells. These results demonstrate that biochemical changes within a single cell line can be sorted via an integrin activity-based assay using simultaneous SERS and O-PTIR.
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- Award ID(s):
- 2117225
- PAR ID:
- 10549024
- Publisher / Repository:
- American Chemical Society
- Date Published:
- Journal Name:
- Analytical Chemistry
- ISSN:
- 0003-2700
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1021/acs.analchem.4c02685
