Magnetic field affects enzymatic ATP synthesis

The rate of ATP synthesis by creatine kinase extracted from V. xanthia venom was shown to depend on the magnetic field. The yield of ATP produced by enzymes with Mg-24(2+) and Mg-26(2+) ions in catalytic sites increases by 7-8% at 55 mT and then decreases at 80 mT. For enzyme with Mg-25(2+) ion in a catalytic site, the ATP yield increases by 50% and 70% in the fields 55 and 80 mT, respectively. In the Earth field the rate of ATP synthesis by enzyme, in which Mg2+ ion has magnetic nucleus Mg-25, is 2.5 times higher than that by enzymes, in which Mg2+ ion has nonmagnetic, spinless nuclei Mg-24 or Mg-26. Both magnetic field effect and magnetic isotope effect demonstrate that the ATP synthesis is an ion-radical process, affected by Zeeman interaction and hyperfine coupling in the intermediate ion-radical pair.