Modulation of channel activity and gadolinium block of MscL by static magnetic fields.
The magnetic field of the Earth has for long been known to influence the behaviour and orientation of a variety of living organisms. Experimental studies of the magnetic sense have, however, been impaired by the lack of a plausible cellular and/or molecular mechanism providing meaningful explanation for detection of magnetic fields by these organisms. Recently, mechanosensitive (MS) ion channels have been implied to play a role in magnetoreception. In this study we have investigated the effect of static magnetic fields (SMFs) of moderate intensity on the activity and gadolinium block of MscL, the bacterial MS channel of large conductance, which has served as a model channel to study the basic physical principles of mechanosensory transduction in living cells. In addition to showing that direct application of the magnetic field decreased the activity of the MscL channel, our study demonstrates for the first time that SMFs can reverse the effect of gadolinium, a well-known blocker of MS channels. The results of our study are consistent with a notion that (1) the effects of SMFs on the MscL channels may result from changes in physical properties of the lipid bilayer due to diamagnetic anisotropy of phospholipid molecules and consequently (2) cooperative superdiamagnetism of phospholipid molecules under influence of SMFs could cause displacement of Gd(3+) ions from the membrane bilayer and thus remove the MscL channel block.
Petrov
Evgeny
E
School of Biomedical Sciences, University of Queensland, St Lucia, Brisbane, QLD 4072, Australia.
Martinac
Boris
B
D004307:Dose-Response Relationship, Radiation; D004574:Electromagnetic Fields; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000528:radiation effects*; D005682:Gadolinium / Q000737:chemistry*; D015640:Ion Channel Gating / Q000528:radiation effects*; D007473:Ion Channels / Q000737:chemistry* / Q000528:radiation effects*; D008051:Lipid Bilayers / Q000737:chemistry* / Q000528:radiation effects; D008081:Liposomes / Q000737:chemistry* / Q000528:radiation effects; D011487:Protein Conformation / Q000528:radiation effects; D011829:Radiation Dosage
D029968:Escherichia coli Proteins; D007473:Ion Channels; D008051:Lipid Bilayers; D008081:Liposomes; C086596:MscL protein, E coli; D005682:Gadolinium