Tuesday, February 20, 2007

Shape-shifting molecular motor in your ear

Prestin is a membrane protein found in the hair cells of the mammalian cochlea and a member of the anion transporter familly. It is essential for hearing in mice, and KOs have a 40-60dB (>100 fold) loss in hearing sensitivity. It is essentially a direct voltage to displacement motor, that does not use ATP and is the fastest molecular motor identified by several orders of magnitude. In response to the change in voltage (Cl and bicarbonate) the Prestin changes the shape of the cell and the stiffness of the hair. When overexpressed in kidney cells, it could still work in the same way and induce shape-shifting. Interestingly it can also work in the other way around and transform movement into voltage, making a molecular generator. Of course the DNA sequence was rapidly patented in 2003, and now NASA is taking interest in it and wants to make bugs that can make energy to insert into astronaut's space suits and power them by their movement. Sounds far out, but really I can't wait until we start building nano-robots with it...