Medical/biological study (experimental study)

Enhancement of the hydrolysis activity of F0F1-ATPases using 60 Hz magnetic fields med./bio.

By: Chen C, Cui Y, Yue J, Huo X, Song T

Published in: Bioelectromagnetics 2009; 30 (8): 663-668

F₀F₁-ATPase is composed of two parts, membrane-embedded part F0 and hydrophilic catalytic part F1. F₀F₁-ATPase interconverts two major "energy currencies" (the transmembrane electrochemical potential difference of protons and ATP).
F₀F₁-ATPases were also treated with N,N-dicyclohexylcarbodiimide (DCCD, for inhibition of subunit F0) and lithium chloride (also for hydrolysis inhibition). Additionally, the chromatophores were labeled with the pH indicator F-DHPE (proton transfer experiment (function of F0 is the proton transfer)).

Exposure	Parameters
Exposure 1: 60 Hz Exposure duration: continuous for 20 min	magnetic flux density: 0.1 mT minimum magnetic flux density: 0.5 mT maximum

Exposure source	coil(s)
Setup	two 12 cm x 6 cm rectangular coils; each coil consisting of two sub-coils with 100 turns of 1 mm copper wire each, separated by 7 cm; non-uniformity of the magnetic field in the exposue aerea < 2%
Sham exposure	A sham exposure was conducted.

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	0.1 mT	minimum	measured	-	-
magnetic flux density	0.5 mT	maximum	measured	-	-

Exposed system:

molecular biosynthesis: enzyme activity of F₀F₁-ATPase (hydrolysis activity; maximum rate of ATP hydrolyzed per unit of enzyme per unit of time, measured by luciferin/luciferase system)
pH of the chromatophores (spectrophotometry of F-DHPE labeled chromatophores)

Investigated system:

Time of investigation:

60 Hz magnetic fields enhanced the enzyme activity of F₀F₁-ATPase. The effects depended on magnetic intensity: 0.3 and 0.5 mT magnetic fields enhanced the hydrolysis activity, whereas 0.1 mT exposure caused no significant changes. The magnetic fields mainly affected the subunit F1: even if the F₀F₁-ATPase was inhibited by DCCD (inhibition of F0), its hydrolysis activity was enhanced by a 0.5 mT magnetic field. Moreover, when the F-DHPE-labeled chromatophores were exposed to 0.5 mT, it was found that the pH of the outer membrane of the chromatophore was unchanged.
The data may provide a new way to explore a relationship between the effects of magnetic fields on human health and the effects of magnetic fields on membrane F₀F₁-ATPase (F1 may be the target affected by magnetic fields).

Study character:

Nikolic LM et al. (2010): Effect of alternating the magnetic field on phosphate metabolism in the nervous system of Helix pomatia
Zrimec A et al. (2002): Alternating electric fields stimulate ATP synthesis in Escherichia coli
Blank M et al. (2001): Optimal frequencies for magnetic acceleration of cytochrome oxidase and Na,K-ATPase reactions
Blank M et al. (1997): Frequency dependence of Na,K-ATPase function in magnetic fields
Blank M et al. (1996): The threshold for Na,K-ATPase stimulation by electromagnetic fields
Blank M et al. (1995): Effects of low frequency magnetic fields on Na,K-ATPase activity
Martirosov S et al. (1995): Inhibition of F0F1-H+-ATPase activity in ac fields
Blank M et al. (1993): The Na, K-ATPase as a model for electromagnetic field effects on cells
Blank M et al. (1992): Threshold for inhibition of Na, K-ATPase by ELF alternating currents
Blank M et al. (1992): Temperature dependence of elctric field effects on Na,K-ATPase
Vinkler C et al. (1982): Characterization of external electric field-driven ATP synthesis in chloroplasts
Witt HT et al. (1976): Membrane-bound ATP synthesis generated by an external electrical field