The choice was done among integral membrane proteins (calcium-ATPase, sodium potassium ATPase, succinate dehydrogenase), peripheral membrane proteins (photoreceptor phosphodiesterase 6), and lipid-linked proteins (alkaline phosphatase, acetylcholinesterase).
No parameters are specified for this exposure.
The activities of three enzymes out of seven exposed to the electromagnetic field decreased approximately of about 54-61 % with field amplitudes above a threshold of 73-151 µT depending on the enzyme. The same field had no effect on the activities of either integral membrane enzymes such as calcium-ATPase, sodium potassium ATPase, succinate dehydrogenase or peripheral membrane enzymes (photoreceptor phosphodiesterase 6).
The decrease in enzyme activity of the field-sensitive enzymes was independent of the time of permanence in the electromagnetic field and was completely reversible. When these enzymes were solubilized with Triton, no effect of the field was revealed on the enzyme activity, suggesting the crucial role of the membrane in determining the conditions for enzyme inactivation.