Analysis of the migration behaviour of single microtubules in electric fields
| Autor: | Konrad J. Böhm, Jack A. Tuszynski, Unger E, L Wollweber, Roland Stracke |
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| Rok vydání: | 2002 |
| Předmět: |
Models
Molecular Paclitaxel Protein Conformation Swine Dimer Movement Biophysics macromolecular substances Biochemistry Microtubules chemistry.chemical_compound Microtubule Tubulin Electric field Animals Molecular Biology Microtubule nucleation Microscopy Video biology Chemistry Charge density Brain Cell Biology Electric Stimulation Electrophoresis Crystallography Isoelectric point biology.protein |
| Zdroj: | Biochemical and biophysical research communications. 293(1) |
| ISSN: | 0006-291X |
| Popis: | By video contrast microscopy, individual microtubules formed from pure tubulin in the presence of taxol were studied in constant electric fields. At nearly physiological conditions, i.e., in a buffer at pH 6.8 and 120 mM ionic strength, suspended microtubules moved towards the anode with an electrophoretic mobility of approximately 2.6×10 −4 cm 2 / V s , corresponding to an unbalanced negative charge of 0.19 electron charges per tubulin dimer. Strikingly, this value is lower by a factor of at least 50 than that calculated from crystallographic data for the non-assembled tubulin dimer. Moreover, the taxol-stabilized microtubules had an isoelectric point of about pH 4.2 which is significantly lower than that known for the tubulin monomers. This indicates that microtubule formation is accompanied by substantial changes of charge distribution within the tubulin subunits. Constant electric fields were shown to affect also the orientation of microtubules gliding across a kinesin-coated surface at pH 6.8. |
| Databáze: | OpenAIRE |
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