Biomedical Engineering Reference
In-Depth Information
Fig. 6.15.
Modes of operation of motility assays for linear molecular motors
(Reprinted with permission from [60]. Copyright 2001 Academic Press Inc Elsevier
Science)
Linear Motors
Apparently, linear motors have been studied more intensively than rotary
ones because of the directed motion which can be used for transport of car-
gos. Linear motors are comprised of two protiens operating in tandem, i.e. the
filament (F-actin or microtubules, MTs) and the motor (myosin, or kinesin,
respectively). As mentioned before, motility assays are effectively primitive
hybrid dynamic nanodevices, which can have two generic architectures: (i) a
gliding geometry with the surface functionalized with the motor protein and
the filament/MT sliding atop, possibly carrying a fluorescent tag; or (ii) an
inverted, or bead, geometry with the filaments/MTs immobilized on the sur-
face and the motor proteins, which are immobilized on cargo beads, 'walking'
on tracks. Fig. 6.15 [60] presents the two motility assay geometries for the
kinesin/MT system. Motility assays, which have been proposed for almost 2
decades for both actin-myosin [61] and kinesin-MT [62] systems, are still the
technological paradigm of hybrid dynamic nano-devices based on molecular
