Tubulin dipole moment, dielectric constant and quantum behavior: computer simulations, experimental results and suggestions

Biosystems. 2004 Nov;77(1-3):73-85. doi: 10.1016/j.biosystems.2004.04.003.


We used computer simulation to calculate the electric dipole moments of the alpha- and beta-tubulin monomers and dimer and found those to be |p(alpha)| = 552D, |p(beta)| = 1193D and |p(alphabeta)| = 1740D, respectively. Independent surface plasmon resonance (SPR) and refractometry measurements of the high-frequency dielectric constant and polarizability strongly corroborated our previous SPR-derived results, giving Deltan/Deltac approximately 1.800 x 10(-3)ml/mg. The refractive index of tubulin was measured to be n(tub) approximately 2.90 and the high-frequency tubulin dielectric constant k(tub) approximately 8.41, while the high-frequency polarizability was found to be alpha(tub) approximately 2.1 x 10(-33)C m(2)/V. Methods for the experimental determination of the low-frequency p are explored, as well as ways to test the often conjectured quantum coherence and entanglement properties of tubulin. Biobits, bioqubits and other applications to bioelectronics are discussed.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Computer Simulation
  • Computers, Molecular*
  • Electric Conductivity
  • Electric Impedance
  • Electrochemistry / methods
  • Microtubules / chemistry*
  • Microtubules / ultrastructure*
  • Models, Chemical*
  • Models, Molecular*
  • Protein Conformation
  • Quantum Theory
  • Refractometry / methods
  • Structure-Activity Relationship
  • Surface Plasmon Resonance / methods
  • Tubulin / chemistry*
  • Tubulin / ultrastructure*


  • Tubulin