ULTIMATE COMPUTING - Quantum Consciousness Studies

98 Cytoskeleton/Cytocomputer
requires contractile MAPs spaced between 15 and 25 nanometers apart along MT
lengths. Many other MAP binding patterns are spirals which wind around MT
cylinders in super-helices, and several theories suggest how these sites can be
determined. These include linear sequencing of varying tubulin isozymes along
protofilaments (Kim, 1986), crystal symmetry describing each MAP terrain
(Figure 5.17, Koruga, 1986) or by the lattice steps necessary to get from one MAP
site to its nearest neighbor MAP. For example, electron micrographs of MAP-MT
binding by Burns (1978) clearly show MAP binding which may be described as
“over 3, up 1.” That is, if the tubulin subunit to which the MAP is bound is the
starting point, moving 3 monomers along the leftward row helix, and then up 1
monomer along the protofilament will indicate the next attachment site. A number
of geometrical super-helical patterns have been observed which match other
“chess-like” movement rules. These are shown in Figures 5.12–5.15. In other
instances such as brain MAPs, attachment patterns are irregular and
heterogeneous, and thus are capable of representing information.
Figure 5.13: Patterns of MAP attachment to microtubules observed by electron
microscopy (Burns, 1978; Kim et al., 1986; and others).
Rod shaped bridges which occur between MT are of at least two sorts. Motion
producing protein “arms” which consume ATP hydrolysis energy to generate
force are analogous to myosin bridges of skeletal muscle. Moving arms attached
to MT are made of proteins called kinesin and dynein. Dynein arms on MT which
contract in organized sequences to produce collective movements were first
described and characterized in cilia and flagella by Ian Gibbons (1968). The arms
reside at periodic intervals along the outer MT within cilia and flagella. They