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We recently introduced a method to tether intact phospholipid vesicles onto a fluid supported lipid bilayer using DNA hybridization (Yoshina-Ishii, C.; Miller, G. P.; Kraft, M. L; Kool, E. T.; Boxer, S. G. J. Am. Chem. Soc. 2005, 127, 1356-1357). Once tethered, the vesicles can diffuse in two dimensions parallel to the supported membrane surface. The average diffusion coefficient, D, is typically 0.2 microm(2)/s; this is 3-5 times smaller than for individual lipid or DNA-lipid conjugate diffusion in supported bilayers. In this article, we investigate the origin of this difference in the diffusive dynamics of tethered vesicles by single-particle tracking under collision-free conditions. D is insensitive to tethered vesicle size from 30 to 200 nm, as well as a 3-fold change in the viscosity of the bulk medium. The addition of macromolecules such as poly(ethylene glycol) reversibly stops the motion of tethered vesicles without causing the exchange of lipids between the tethered vesicle and supported bilayer. This is explained as a depletion effect at the interface between tethered vesicles and the supported bilayer. Ca ions lead to transient vesicle-vesicle interactions when tethered vesicles contain negatively charged lipids, and vesicle diffusion is greatly reduced upon Ca ion addition when negatively charged lipids are present both in the supported bilayer and tethered vesicles. Both effects are interesting in their own right, and they also suggest that tethered vesicle-supported bilayer interactions are possible; this may be the origin of the reduction in D for tethered vesicles. In addition, the effects of surface defects that reversibly trap diffusing vesicles are modeled by Monte Carlo simulations. This shows that a significant reduction in D can be observed while maintaining normal diffusion behavior on the time scale of our experiments.
Chiaki Yoshina-Ishii, and
Yee-Hung M Chan, and
Joseph M Johnson, and
Li A Kung, and
Peter Lenz, and
Steven G Boxer
October 2018,
Langmuir : the ACS journal of surfaces and colloids,
Chiaki Yoshina-Ishii, and
Yee-Hung M Chan, and
Joseph M Johnson, and
Li A Kung, and
Peter Lenz, and
Steven G Boxer
January 1997,
Annual review of biophysics and biomolecular structure,
Chiaki Yoshina-Ishii, and
Yee-Hung M Chan, and
Joseph M Johnson, and
Li A Kung, and
Peter Lenz, and
Steven G Boxer
March 2018,
The Journal of chemical physics,
Chiaki Yoshina-Ishii, and
Yee-Hung M Chan, and
Joseph M Johnson, and
Li A Kung, and
Peter Lenz, and
Steven G Boxer
October 2021,
Biophysics reports,
Chiaki Yoshina-Ishii, and
Yee-Hung M Chan, and
Joseph M Johnson, and
Li A Kung, and
Peter Lenz, and
Steven G Boxer
October 2007,
Physical biology,
Chiaki Yoshina-Ishii, and
Yee-Hung M Chan, and
Joseph M Johnson, and
Li A Kung, and
Peter Lenz, and
Steven G Boxer
January 2008,
Chromosome research : an international journal on the molecular, supramolecular and evolutionary aspects of chromosome biology,
Chiaki Yoshina-Ishii, and
Yee-Hung M Chan, and
Joseph M Johnson, and
Li A Kung, and
Peter Lenz, and
Steven G Boxer
April 2003,
Biophysical journal,
Chiaki Yoshina-Ishii, and
Yee-Hung M Chan, and
Joseph M Johnson, and
Li A Kung, and
Peter Lenz, and
Steven G Boxer
July 2000,
Biophysical journal,
Chiaki Yoshina-Ishii, and
Yee-Hung M Chan, and
Joseph M Johnson, and
Li A Kung, and
Peter Lenz, and
Steven G Boxer
April 2003,
Physical review. E, Statistical, nonlinear, and soft matter physics,
Chiaki Yoshina-Ishii, and
Yee-Hung M Chan, and
Joseph M Johnson, and
Li A Kung, and
Peter Lenz, and
Steven G Boxer
January 2023,
Life (Basel, Switzerland),
