Molecular and Nanometer-Scale Self-Organized System Generated by Protein Motor Functions

Abstract

Creatures have evolved extremely intelligent and complex adaptive systems for conducting their movements. They are protein motors with typical sizes of a few tens of nanometers. Protein motors include three major protein families, myosin, kinesin and dynein, which participate in a wide range of cellular processes, using energy from the hydrolysis of adenosinetriphosphate ATP. To harness these protein motors to power nanometer-scale devices, we have investigated effective and non-destructive methods for immobilizing protein motors on surfaces and to arrange the output of these motors, e.g. force and movement, to be in a defined direction. We found NEB-22 to be useful for retaining the abilities of protein motors to support the movement of protein filaments. We fabricated various patterns of tracks of NEB-22 on coverslips and protein motors were introduced and immobilized on glass surface. The trajectories of protein polymers were confined to these tracks. Simple patterns readily biased and guide polymer movement confining it to be unidirectional. In addition, having used dynein c purified from Chlamydomonas flagellar axoneme, we showed that microtubules driven by surface-bound dynein were self-organized into dynamic streams through collisions between the microtubules and their subsequent joining.

Climbing Rates of Microtubules Propelled by Dynein after Collision with Microfabricated Walls

“…35) The effect of the surface material is more clearly observed in the case of OEBR1000, on which no microtubules moved, which is consistent with a previous report. 30) The difference in the behaviors of microtubules on OEBR1000 and SAL601 is consistent with the difference in the ratio of the microtubules crossing over the walls. Because dynein on SAL601 retains its function for motility, dynein on the SAL601 wall produces a force that makes microtubules climb the wall.…”

“…The details of the preparation of dynein and microtubules are similar to those in a previous report. 30) A flow cell was made from a coverslip and a Si substrate having walls with two double-sided tapes as spacers. The basic procedures of motility assay are as follows.…”

“…On the other hand, those for the microtubules' motion driven by dynein have not yet been reported, except for previous reports in which dynein on SiO 2 kept its function and the microtubule's trajectories were regulated with a wall made of a negative resist polymer (NEB-22). 30) The behaviors of microtubules driven by dynein c (axonemal dynein) at the collision with the wall were also examined and simulated. 31) To estimate the efficiency of the height, material, and profile of a wall, we fabricated a guiding wall that makes microtubules collide with a target wall perpendicularly and counted the number of those crossing over it.…”

Quantitative characterization of guided motion of dynein-microtubule system

“…The details of the preparation of dynein and microtubule was similar to the previous report [4]. We used axonemal dynein that is extracted from outer-armless mutant of chlamydomonas.…”