First film of molecular motor

First film of molecular motor

A molecule that functions like a rotary motor, one of nature's most amazing engineering feats, has been filmed in action for the first time by scientists. The motor, which measures just 10 millionths of a millimetre across, is part of the complex mechanism of respiration by which cells release energy from food.

It works like the rotor arm in a car's distributor. A central spindle turns within a barrel and makes contact with the "points" - three chemical activation sites which are triggered in turn, in a similar way to spark- plugs in a car.

For some time, scientists have suspected that the "motor", a component of an enzyme that acts as a catalyst in the process of respiration, functions in this way. Now scientists from the Tokyo Institute of Technology, Yokohama, Japan, have proved conclusively that this happens - by filming the motor spinning. The team, led by Masasuke Yoshida, attached a tiny fluorescent filament to the "rotor arm", allowing its movement to be seen.