The protective effect of osmoprotectant TMAO on bacterial mechanosensitive channels of small conductance MscS/MscK
Evgeny Petrov1, Paul R Rohde, Bruce Cornell
1Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia. petrov67@gmail.com
Abstract:
Activity of the bacterial mechanosensitive channels of small conductance MscS/MscK of E. coli was investigated under high hydrostatic pressure (HHP) using the "flying-patch" patch-clamp technique. The channels were gated by negative pipette voltage and their open probability was measured at HHP of 0.1 to 80 MPa. The channel open probability decreased with increasing HHP. When the osmolyte methylamine N-oxide (TMAO) was applied to the cytoplasmic side of the inside-out excised membrane patches of E. coli giant spheroplasts the inhibitory effect of HHP on the channel activity was suppressed at pressures of up to 40 MPa. At 40 MPa and above the channel open probability decreased in a similar fashion with or without TMAO. Our study suggests that TMAO helps to counteract the effect of HHP up to 40 MPa on the MscS/MscK open state by "shielding" the cytoplasmic domain of the channels.
Related Concept Videos
Factors Influencing Microbial Growth: Osmolarity
Osmosis and Osmotic Pressure of Solutions
Mechanically-gated Ion Channels
Osmotic Pressure
Ion Channels
Ion channels are specialized integral membrane proteins on the plasma membrane that allow specific...
Deep Sea Microbial Ecology


