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Distinguishing Positional Uncertainty from True Mobility in Single-Molecule Trajectories That Exhibit Multiple Diffusive Modes

Published online by Cambridge University Press:  05 July 2012

Mark Kastantin  and
Daniel K. Schwartz
Mark Kastantin
Affiliation:
Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO 80309, USA
Daniel K. Schwartz*
Affiliation:
Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO 80309, USA
*
Corresponding author. E-mail: daniel.schwartz@colorado.edu
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Abstract

Although imperfect spatial localization in single-molecule object tracking experiments has long been recognized to induce apparent motion in an immobile population of molecules, this effect is often ignored or incorrectly analyzed for mobile molecules. In particular, apparent motion due to positional uncertainty is often incorrectly assigned as a distinct diffusive mode. Here we show that, due to both static and dynamic contributions, positional uncertainty does not introduce a new apparent diffusive mode into trajectories, but instead causes a systematic shift of each measured diffusion coefficient. This shift is relatively simple: a factor of σ2/Δt is added to each diffusion coefficient, where σ is the positional uncertainty length scale and Δt is the time interval between observations. Therefore, by calculating the apparent diffusion coefficients as a function of Δt, it is straightforward to separate the true diffusion coefficients from the effective positional uncertainty. As a concrete demonstration, we apply this approach to the diffusion of the protein fibrinogen adsorbed to a hydrophobic surface, a system that exhibits three distinct modes of diffusion.

Keywords

diffusiontotal internal reflection fluorescence microscopy (TIRFM)fibrinogenstatic errordynamic errorsingle molecule
Type
Biological Applications: Techniques, Software, and Equipment Development
Information
Microscopy and Microanalysis , Volume 18 , Issue 4 , August 2012 , pp. 793 - 797
Copyright
Copyright © Microscopy Society of America 2012

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References

Bobroff, N. (1986). Position measurement with a resolution and noise-limited instrument. Rev Sci Instrum 57, 1152–1157.CrossRefGoogle Scholar
Bychuk, O.V. & Oshaughnessy, B. (1994). Anomalous diffusion of surface-active species at liquid-fluid and liquid-solid interfaces. J Phys II 4, 1135–1156.Google Scholar
Ciobanasu, C., Harms, E., Tunnemann, G., Cardoso, M.C. & Kubitscheck, U. (2009). Cell-penetrating Hiv1 tat peptides float on model lipid bilayers. Biochemistry 48, 4728–4737.CrossRefGoogle ScholarPubMed
Deschout, H., Neyts, K. & Braeckmans, K. (2012). The influence of movement on the localization precision of sub-resolution particles in fluorescence microscopy. J Biophoton 5, 97–109.CrossRefGoogle ScholarPubMed
Fujiwara, T., Ritchie, K., Murakoshi, H., Jacobson, K. & Kusumi, A. (2002). Phospholipids undergo hop diffusion in compartmentalized cell membrane. J Cell Biol 157, 1071–1081.CrossRefGoogle ScholarPubMed
Honciuc, A., Baptiste, D.J., Campbell, I.P. & Schwartz, D.K. (2009). Solvent dependence of the activation energy of attachment determined by single molecule observations of surfactant adsorption. Langmuir 25, 7389–7392.CrossRefGoogle ScholarPubMed
Honciuc, A. & Schwartz, D.K. (2009). Probing hydrophobic interactions using trajectories of amphiphilic molecules at a hydrophobic/water interface. J Am Chem Soc 131, 5973–5979.CrossRefGoogle Scholar
Kastantin, M., Langdon, B.B., Chang, D.L. & Schwartz, D.K. (2011). Single-molecule resolution of interfacial fibrinogen behavior: Effects of oligomer populations and surface chemistry. J Am Chem Soc 133, 4975–4983.CrossRefGoogle ScholarPubMed
Kastantin, M. & Schwartz, D.K. (2011). Connecting rare DNA conformation and surface dynamics using single-molecule resonance energy transfer. ACS Nano 5, 9861–9869.CrossRefGoogle ScholarPubMed
Kues, T., Peters, R. & Kubitscheck, U. (2001). Visualization and tracking of single protein molecules in the cell nucleus. Biophys J 80, 2954–2967.CrossRefGoogle ScholarPubMed
Sako, Y., Minoguchi, S. & Yanagida, T. (2000). Single-molecule imaging of egfr signalling on the surface of living cells. Nat Cell Biol 2, 168–172.CrossRefGoogle ScholarPubMed
Savin, T. & Doyle, P.S. (2005). Static and dynamic errors in particle tracking microrheology. Biophys J 88, 623–638.CrossRefGoogle ScholarPubMed
Thompson, R.E., Larson, D.R. & Webb, W.W. (2002). Precise nanometer localization analysis for individual fluorescent probes. Biophys J 82, 2775–2783.CrossRefGoogle ScholarPubMed
Walder, R. & Schwartz, D.K. (2010). Single molecule observations of multiple protein populations at the oil-water interface. Langmuir 26, 13364–13367.CrossRefGoogle ScholarPubMed
Walder, R.B., Honciuc, A. & Schwartz, D.K. (2010). Phospholipid diffusion at the oil-water interface. J Phys Chem B 114, 11484–11488.CrossRefGoogle ScholarPubMed
Wu, D.M., Liu, Z.W., Sun, C. & Zhang, X. (2008). Super-resolution imaging by random adsorbed molecule probes. Nano Lett 8, 1159–1162.CrossRefGoogle ScholarPubMed
Yildiz, A., Tomishige, M., Vale, R.D. & Selvin, P.R. (2004). Kinesin walks hand-over-hand. Science 303, 676–678.CrossRefGoogle ScholarPubMed