Magnetic Field Effects on B ₁₂ Ethanolamine Ammonia Lyase: Evidence for a Radical Mechanism

Abstract

A change in radical pair recombination rates is one of the few mechanisms by which a magnetic field can interact with a biological system. The kinetic parameter Vmax/Km (where Km is the Michaelis constant) for the coenzyme B12-dependent enzyme ethanolamine ammonia lyase was decreased 25 percent by a static magnetic field near 0.1 tesla (1000 gauss) with unlabeled ethanolamine and decreased 60 percent near 0.15 tesla with perdeuterated ethanolamine. This effect is likely caused by a magnetic field-induced change in intersystem crossing rates between the singlet and triplet spin states in the [cob(II)alamin:5'-deoxyadenosyl radical] spin-correlated radical pair.

The phorbol 12‐myristate 13‐ acetate (PMA)‐induced oxidative burst in rat peritoneal neutrophils is increased by a 0.1 mT (60 Hz) magnetic field

“…Recently, MF have been observed to modulate intersystem crossing rates of free radical driven enzyme reactions (e.g. B t 2 ethanolamine ammonia lyase) [15]. Nevertheless, alternative explanations cannot be eliminated by our results; for example, MF may affect activation of the respiratory burst by PMA.…”

Are biochemical reactions affected by weak magnetic fields?

“…The third case was an unsuccessful attempt by Harris et al (15) to replicate the observation that the growth of Arabidopsis thaliana seedlings was significantly affected by magnetic fields as weak as 500 μT (16). The authors of the three original studies (13,14,16) have yet to respond in print; in no case is it clear why independent replication proved impossible.…”

Quantum Coherence and Sensitivity of Avian Magnetoreception

“…Here we utilize the results of two behavioral experiments conducted on European Robins to argue that the average life-time of the radical pair is of the order of a microsecond and therefore agrees with experimental estimations of this parameter for cryptochrome -a pigment believed to form the radical pairs. We also found a reasonable parameter regime where sensitivity of the avian compass is enhanced by environmental noise, showing that long coherence time is not required for navigation and may even spoil it.PACS numbers: 03.65.Yz, Recently there has been a growing interest in the application of quantum mechanics to understand many biological phenomena such as photosynthesis [1][2][3][4][5][6][7], process of olfaction [8,9], enzymatic reactions [10,11] or avian magnetoreception [12][13][14][15]. These interests have brought physicists, chemists, and biologists at the same platform and led to the beginning of a new interdisciplinary subject called quantum biology [16,17].…”