Movement and Alignment of Microtubules in Electric Fields and Electric-Dipole-Moment Estimates.

Autor: Böhm, Konrad J., Mavromatos, Nikolaos E., Michette, Alan, Stracke, Roland, Unger, Eberhard
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Zdroj: Electromagnetic Biology & Medicine; 2005, Vol. 24 Issue 3, p319-330, 12p, 1 Black and White Photograph
Abstrakt: The effects of both constant (up to 2 × 10 3 V/m) and high-frequency alternating fields (up to 2.1 × 10 5 V/m, 200 kHz to 2 MHz) on suspended microtubules are investigated. At pH 6.8 and 120 mM ionic strength, constant fields cause a motion of microtubules toward the anode. The electrophoretic mobility amounts to 2.6 × 10 -4 cm 2 /Vs, reflecting a negative net charge of approximately 0.2 elementary charges per tubulin dimer. The moving microtubules are randomly space oriented. Alternating high-frequency fields induce electric dipoles and align the microtubules parallel to the field direction. By determining the angular velocity of the turning microtubules, we estimate a dipole moment of roughly 34,000 Debye at 2.1 × 10 5 V/m and 2 MHz. By comparing the potential energy of the dipole in the applied field with the thermal energy of microtubules, we obtain a minimum value of 6,000 Debye as necessary for an efficient alignment. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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