Abdalla et al. (2001) suggested that the vicinal water of the brain microtubules
generates electromagnetic sine-Gordon solitons propagating with velocity
calculated from the equations:
(107) υ0
= V ∙^-
π Й
= 2p ∫ E ∙ dz
π h
(108) υ0
where z is the length of the microtubule, E is the electric field intensity and p is
the permanent electric of water (p=6.2 x 10 - 30 Cm). After substitution in the
equation of the obtained value for E=10 V/m and for microtubule with length
z=50μm we find soliton velocity:
(109)
υ0 =
2×6.2×10-30Cm×10V.m-1 ×5×10-5m
3.14 × 1.055 × 10-34 Js
= 18.7m.s-1
Although the result is an order of magnitude less than the result presented in
Abdalla et al. (2001) that calculate νo~140m∕s, it shows that fast dissipationless
transport of energy could be achieved by collective water molecule dynamics.
However the phenomenon per se could not account for explaining the
cytoskeletal and microtubule function as being not specific. Indeed proper link
with specific protein conformational states must be found if this transfer of energy
is supposed to be biologically important. From the presented experimental data
and the calculations done in the paper we have seen that α <-> β tubulin
‘switches’ could not account for biologically feasible model of subneuronal
processing of information. This problem is potentially solvable if we focus our
attention on the microtubule outer surface and the microtubule <-> MAP and
microtubule <-> motor protein interaction. Responsible for the MAP and motor
protein control are tubulin C-terminal projections that are highly acidic
(hydrophilic) and flexible (allowing multiple conformations with low energy barrier
heights).
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