Protein motors for future molecular and nano-bio-machines

D.Y. Li

Department of Chemical and Materials Engineering Department of Bio-medical Engineering University of Alberta, Edmonton, Alberta, Canada T6G 2V4

Muscle contraction is achieved by the interaction between actin filaments and motor proteins

WHIPLIKE TAILS, found on many bacteria, are propelled by protein motors. The tiny biochemical motor turns a rotary shaft that spins the tails, or flagella, and allows the bacteria, such as these E. coli, to move through liquid.

Living creatures move, driven by motor proteins

Classification of protein motors

50 nmBurgess-Oiwa model (linear motion)

Burgess et al, Nature (2003)

Protein motors would be useful as engines to drive bio-filamentssuch as microtubules (as a medium) for power transfer in future

bio-nano-devices

Since a number of bio-filaments are involved, the interactionbetween the filaments influences their movement:

1) Microtubule joining or interaction2) Self-organization of microtubules

Protein motors have the potential as a biological engine for nano-bio-devices

Microtubule joining

When meeting, a microtubule has the tendency to move together with the other, no matter theymove in similar directions or in opposite directions. The joining involves bending and rotation of microtubules, which is energy-controlled.

Self-organization of microtubulesWhen a large number of microtubules moving in a system, they may move in a self-organizedform with the formation of circular patterns as shown in the left-hand side figure. A computersimulation study suggests that the self-organization of microtubules is caused by microtubulebias and their mutual interaction or joining (see the right-hand side movie).

The circular patterns from the self-organizedmovement of microtubules Computer simulated self-organization of microtubules

driven by dynein c (one type of protein motors).