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Calmodulin‐dependent cyclic nucleotide phosphodiesterase activity is altered by 20 μT magnetostatic fields
Author(s) -
Liboff A.R.,
Cherng S.,
Jenrow K.A.,
Bull A.
Publication year - 2003
Publication title -
bioelectromagnetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.435
H-Index - 81
eISSN - 1521-186X
pISSN - 0197-8462
DOI - 10.1002/bem.10063
Subject(s) - calmodulin , cyclic nucleotide phosphodiesterase , chemistry , calcium , biophysics , myosin light chain kinase , phosphodiesterase , magnetic field , nucleotide , nuclear magnetic resonance , myosin , enzyme , biochemistry , physics , biology , organic chemistry , quantum mechanics , gene
Absorbance measurements at 660 nm of calmodulin (CaM) dependent cyclic nucleotide phosphodiesterase activity under cell free conditions indicate that 30‐min exposures to weak magnetostatic field intensities alters this activity, compared to zero magnetic field exposures. This effect depends nonlinearly on the concentration of free calcium, with maximum magnetic interaction apparently occurring at an optimal Ca 2+ concentration corresponding to 50% activation (EC 50 ). If one regards Ca 2+ /CaM activation as a switching process, then increasing the magnetic field at Ca 2+ levels in excess of optimal acts to bias this switch towards lower calcium concentrations. A magnetic dependence has been previously reported by others in an homologous system, CaM dependent myosin light chain phosphorylation, implying that there may be an underlying magnetic interaction that involves the initial Ca 2+ /CaM binding process common to both enzymatic pathways. The level of magnetostatic intensity at which this effect is observed (∼20 μT) implies that CaM activation may be functionally sensitive to the geomagnetic field. Bioelectromagnetics 24:32–38, 2003. © 2002 Wiley‐Liss, Inc.