Radiofrequency remote control of thermolysin activity.

The majority of biological processes are regulated by enzymes, precise control over specific enzymes could create the potential for controlling cellular processes remotely. We show that the thermophilic enzyme thermolysin can be remotely activated in 17.76 MHz radiofrequency (RF) fields when covalently attached to 6.1 nm gold coated magnetite nanoparticles. Without raising the bulk solution temperature, we observe enzyme activity as if the solution was 16 ± 2 °C warmer in RF fields-an increase in enzymatic rate of 129 ± 8%. Kinetics studies show that the activity increase of the enzyme is consistent with the induced fit of a hot enzyme with cold substrate.