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

Abstract

We used computer simulation to calculate the electric dipole moments of the α- and β-tubulin monomers and dimer and found those to be | p α| = 552D, | p β| = 1193D and | p αβ| = 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 Δ n/Δ c ∼ 1.800 × 10 −3 ml/mg. The refractive index of tubulin was measured to be n tub ∼ 2.90 and the high-frequency tubulin dielectric constant k tub ∼ 8.41, while the high-frequency polarizability was found to be α tub ∼ 2.1 × 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.