Effects of Magnetic Fields on EGFP Fluorescence During Renaturation

In previous work with hen egg white lysozyme, we showed that extremely low-frequency electromagnetic fields (40 μT, 50 Hz) accelerated protein renaturation. In contrast, hypomagnetic fields (<40 nT) slowed renaturation compared to controls (static magnetic field, 40 μT). Here, we investigated the fluorescence of enhanced green fluorescent protein (EGFP) under these magnetic conditions. In a 20% hypomagnetic field environment, the fluorescence intensity of native EGFP decreased. Extremely low-frequency fields (40 μT, 50 Hz) induced a significant blue shift in fluorescence wavelength upon renaturation compared with controls. These effects indicate that fluorescent proteins are effective for studying weak magnetic fields, and the renaturation process may be a target for such fields with induction similar to that of the geomagnetic field.