As discussed below, the structures, biophysical studies and site-directed mutagenesis, revealed the determinants of ligand binding in SitA, and unveiled subtle ligand-induced conformational changes that may underlie the molecular switch required for fruitful receptor engagement and ion transport.
However, the molecular switches and UCNPs have large distance in solution, which severely limits the energy transfer between the components, and thus increases the amount of irradiation time required for the photoreactions to occur.
He and his collaborators throw molecular switches together onto a small wafer with small gold particles.
A major challenge is to figure out how to address the individual molecular switches, Mr. Ellenbogen said.
The clinic says it uses "antineoplastons" – "molecular switches that turn off life processes in abnormal cells" – to treat cancer patients.
At Hewlett-Packard, scientists say they think that they may be able to pair simple logic circuits made out of their molecular switches with silicon transistors that boost the signal before sending it to another molecular circuit.
Molecular switches would not be quicker than their silicon counterparts, but they might be easier and cheaper to make and would run on very low power.
The Yale-Rice team and a group at Harvard also reported creating reversible molecular switches within the last year, but they operated under more limited conditions.
Dr. Tour said he believed that molecular switches would soon be used as digital memory within watches or other small devices.
The "Terminator," for example, was a a set of molecular switches with the ability to turn a plant's genes on and off.
