Radio frequency magnetic field effects on molecular dynamics and iron uptake in cage proteins

Abstract

The protein ferritin has a natural ferrihydrite nanoparticle that is superparamagnetic at room temperature. For native horse spleen ferritin, we measure the low field magnetic susceptibility of the nanoparticle as 2.2 x 10(-6) m(3) kg(-1) and its Néel relaxation time at about 10(-10) s. Superparamagnetic nanoparticles increase their internal energy when exposed to radio frequency magnetic fields due to the lag between magnetization and applied field. The energy is dissipated to the surrounding peptidic cage, altering the molecular dynamics and functioning of the protein. This leads to an increased population of low energy vibrational states under a magnetic field of 30 microT at 1 MHz, as measured via Raman spectroscopy. After 2 h of exposure, the proteins have a reduced iron intake rate of about 20%. Our results open a new path for the study of non-thermal bioeffects of radio frequency magnetic fields at the molecular scale.

Lipid Oxidation Induced by RF Waves and Mediated by Ferritin Iron Causes Activation of Ferritin-Tagged Ion Channels

“…Ferritin is the main cellular iron storage protein (Arosio et al, 2017), and it has been reported that RF waves disturb its capacity to handle iron (Cé spedes and Ueno, 2009;Cé spedes et al, 2010). Next, we tested the effects of RF exposure on the LIP in cells loaded with calcein (Figure 1E).…”

New Horizons in Electromagnetics in Medicine and Biology

“…We studied the effects of RF electromagnetic fields on iron ion release and uptake from and into the ferritins. As shown in Figure 9, we observed that the amount of iron chelated after 1 h is reduced by up to a factor of 3 in proteins previously exposed to RF electromagnetic fields of 1 MHz and 30 μT for 5 h (Céspedes & Ueno, 2009; Cespedes et al., 2010). The error bars in Figure 9 are calculated as the standard error of the mean.…”

Alternating Magnetic Fields Drive Stimulation of Gene Expression via Generation of Reactive Oxygen Species

“…The significant inhibition of RF-AMF driven SEAP production by GSK, with and without capsaicin, suggests that NOX1/2-generated ROS in HEK-293T cells, plays a role in TRPV1 activation, and this ROS is potentiated in the presence of capsaicin. However, even in the absence of capsaicin, ROS may be formed from ferritin upon RF-AMF treatment without a potentiator 33 (Hernandez-Morales et al, 2020), likely due to AMF effecting local iron levels around ferritin 40,41 (Céspedes et al, 2009, 2010). To understand better the role of ROS under RF-AMF conditions, HEK-293T cells stably expressing the αGFPnb-V1/GFP-FtD magnetogenetics construct were exposed to RF-AMF and both intra- and extracellular ROS levels were measured using DCFDA and Amplex Red, respectively.…”