Abstract
The effect of the RNA core on interfacial interactions of the bacteriophage MS2 was investigated. After removal of the RNA core, empty intact capsids were characterized and compared to untreated MS2. Electron density of untreated MS2 and RNA-free MS2 were characterized by transmission electron microscopy (TEM) and synchrotron-based small angle spectroscopy (SAXS). Suspensions of both particles exhibited similar electrophoretic mobility across a range of pH values. Similar effects were observed at pH 5.9 across a range of NaCl or CaCl2 concentrations. We compared key interfacial interactions (particle-particle and particle/air-water interface) between suspensions of each type of particle using time resolved dynamic light scattering (TR-DLS) to observe and quantify aggregation kinetics and axisymmetric drop shape analysis to measure adsorption at the air-water interface. Both suspensions showed insignificant aggregation over 4 h in 600 mM NaCl solutions. In the presence of Ca2+ ions, aggregation of both types of particles was consistent with earlier aggregation studies and was characterized by both reaction-limited and diffusion-limited regimes occurring at similar [Ca2+]. However, the removal of the RNA from MS2 had no apparent effect on the aggregation kinetics of particles. Despite some differences in the kinetics of adsorption to the air-water interface, the changes in surface tension which result from particle adsorption showed no difference between the untreated MS2 and RNA-free MS2. The interactions and structure of particles at the air-water interface were further probed using interfacial dilational rheology. The surface elasticity (E s) and surface viscosity (ηs) at the interface were low for both the untreated virus and the RNA-free capsid. This observation suggests that the factors that impact the adsorption kinetics are not important for an equilibrated interface. © 2011 The Royal Society of Chemistry.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 10449 |
| Journal | Soft Matter |
| Volume | 7 |
| Issue number | 21 |
| DOIs | |
| State | Published - 2011 |
| Externally published | Yes |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-01Acknowledgements: The authors acknowledge the Lafayette College EXCEL scholars research program (ED), and the NSF MRI Grant # 0619409. We also thank Professor Gerard Wong and Dr Nathan Schmidt for the SAXS data. This work was partially supported by the WaterCAMPWS, a Science and Technology Center of Advanced Materials for the Purification of Water with Systems under the National Science Foundation agreement number CTS-0120978, USDA grant no. 2008-35102-19143, and NSF Career grant #0954501. National Aeronautics and Space Agency (NASA) Award NNX10AV26G (JKF). This work is partially funded by the Academic Excellence Alliance (AEA) program at King Abdullah University of Science and Technology (KAUST).
This publication acknowledges KAUST support, but has no KAUST affiliated authors.