A dynamical systems/Larmor precession model for weak magnetic field bioeffects: Ion binding and orientation of bound water molecules

A dynamical systems/Larmor precession model is proposed to describe the kinetics of ion binding at a signaling molecule. A bistable potential well represents the hydrated ion in the outer Helmholtz plane of the electrical double layer at the electrified macromoleculeaqueous interface (unbound), or in the binding site (inner Helmholtz plane, bound). Thermal noise drives the binding process resulting in a chaotic hopping between the two states and producing the characteristic Lorentzian or 1/f power spectrum found in biological systems. It is postulated binding kinetics can be influenced by the precessional motion of bound water in the binding site at the Larmor frequency with a 0.1-1 μT magnetic field threshold in the presence of thermal noise. This modulates bound water orientation angles, causing fluctuations in the instantaneous dielectric constant at the binding site, affecting the kinetics of ion binding. The effect increases with B for static and AC fields (negligible induced E), with no resonances related to the Larmor precession frequency. However a resonance is expected for frequencies at or near the characteristic interwell hopping rate. AC resonance frequencies are expected to increase with increasing temperature and static field. Application to cell-free myosin phosphorylation accurately predicts static magnetic field results in the 1-200 μT range.