• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2009년 추계학술대회논문집
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• pp.97-102
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• 2009

Translocation of biopolymers such as DNA and RNA through a nano-pore is an important process in biotechnology applications. The translocation process of a biopolymer through an artificial nano-pore in the presence of a fluid solvent is simulated. The polymer motion is simulated by Langevin molecular dynamics (MD) techniques while the solvent dynamics are taken into account by lattice-Boltzmann method (LBM). The hydrodynamic interactions are considered explicitly by coupling the polymer and solvent through the frictional and the random forces. From simulation results we found that the hydrodynamic interactions between polymer and solvent speed-up the translocation process. The translocation time ${\tao}_T$ scales with the chain length N as ${{\tau}_T}^{\propto}N^{\alpha}$. The value of scaling exponents($\alpha$) obtained from our simulations are $1.29{\pm}0.03$ and $1.41{\pm}0.03$, with and without hydrodynamic interactions, respectively. Our simulation results are in good agreement with the experimentally observed value of $\alpha$, which is equal to $1.27{\pm}0.03$, particularly when hydrodynamic interaction effects are taken into account.

• Molecules and Cells
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• 제21권1호
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• pp.76-81
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• 2006

Tubulin is synthesized in the cell body and must be delivered to the axon to support axonal growth. However, the exact form in which these proteins, in particular tubulin, move within the axon remains contentious. According to the "polymer transport model", tubulin is transported in the form of microtubules. In an alternative hypothesis, the "short oligomer transport model", tubulin is added to existing, stationary microtubules along the axon. In this study, we measured the translocation of microtubule plus ends in soma segments, the middle of axonal shafts and the growth cone areas, by expressing GFP-EB3 in cultured Xenopus embryonic spinal neurons. We found that none of the microtubules in the three compartments were transported rapidly as would be expected from the polymer transport model. These results suggest that microtubules are stationary in most segments of the axon, thus supporting the model according to which tubulin is transported in nonpolymeric form in rapidly growing Xenopus neurons.