Quantum nanorotator in the hypomagnetic field: Implications for magnetobiology

A mechanism for the biological effects of the hypomagnetic field is proposed, based on the rotational motion of a molecule as a whole within a cavity in an enzyme. It has been shown previously that a molecular rotator about 1 nm in size can have a decoherence time of up to tens of milliseconds. On shorter timescales, the nanorotator exists in a state of quantum superposition and exhibits interference effects. The statics and dynamics of the nanorotator in a magnetic field are analyzed using the Schrödinger and Liouville-von Neumann equations, taking into account chemical kinetics and thermal relaxation. It is demonstrated that the small-scale interference of the nanorotator is highly sensitive to weak magnetic fields. The quantum nanorotator shows magnetic effects ranging from a few to several tens of percent over a wide range of realistic decoherence rates. If the nanorotator constitutes an adequate model of rotating amino acid residues in the active sites of certain enzymes involved in protein synthesis, then weak magnetic fields can exert significant biological effects, leading to the observed phenomena.