The excitable fluid mosaic
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The excitable fluid mosaic. / Heimburg, Thomas.
In: B B A - Biomembranes, Vol. 1865, No. 3, 184104, 01.03.2023.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - The excitable fluid mosaic
AU - Heimburg, Thomas
PY - 2023/3/1
Y1 - 2023/3/1
N2 - The Fluid Mosaic Model by Singer & Nicolson proposes that biological membranes consist of a fluid lipid layer into which integral proteins are embedded. The lipid membrane acts as a two-dimensional liquid in which the proteins can diffuse and interact. Until today, this view seems very reasonable and is the predominant picture in the literature. However, there exist broad melting transitions in biomembranes some 10-20 degrees below physiological temperatures that reach up to body temperature. Since they are found below body temperature, Singer & Nicolson did not pay any further attention to the melting process. But this is a valid view only as long as nothing happens. The transition temperature can be influenced by membrane tension, pH, ionic strength and other variables. Therefore, it is not generally correct that the physiological temperature is above this transition. The control over the membrane state by changing the intensive variables renders the membrane as a whole excitable. One expects phase behavior and domain formation that leads to protein sorting and changes in membrane function. Thus, the lipids become an active ingredient of the biological membrane. The melting transition affects the elastic constants of the membrane. This allows for the generation of propagating pulses in nerves and the formation of ion-channel-like pores in the lipid membranes. Here we show that on top of the fluid mosaic concept there exists a wealth of excitable phenomena that go beyond the original picture of Singer & Nicolson.1
AB - The Fluid Mosaic Model by Singer & Nicolson proposes that biological membranes consist of a fluid lipid layer into which integral proteins are embedded. The lipid membrane acts as a two-dimensional liquid in which the proteins can diffuse and interact. Until today, this view seems very reasonable and is the predominant picture in the literature. However, there exist broad melting transitions in biomembranes some 10-20 degrees below physiological temperatures that reach up to body temperature. Since they are found below body temperature, Singer & Nicolson did not pay any further attention to the melting process. But this is a valid view only as long as nothing happens. The transition temperature can be influenced by membrane tension, pH, ionic strength and other variables. Therefore, it is not generally correct that the physiological temperature is above this transition. The control over the membrane state by changing the intensive variables renders the membrane as a whole excitable. One expects phase behavior and domain formation that leads to protein sorting and changes in membrane function. Thus, the lipids become an active ingredient of the biological membrane. The melting transition affects the elastic constants of the membrane. This allows for the generation of propagating pulses in nerves and the formation of ion-channel-like pores in the lipid membranes. Here we show that on top of the fluid mosaic concept there exists a wealth of excitable phenomena that go beyond the original picture of Singer & Nicolson.1
KW - Thermodynamics
KW - Domains
KW - Rafts
KW - Elastic constants
KW - Ion channels
KW - Nerves
KW - MONTE-CARLO-SIMULATION
KW - LIPID-MEMBRANES
KW - PHASE-TRANSITION
KW - ERYTHROCYTE-MEMBRANE
KW - MELTING TRANSITION
KW - MODEL MEMBRANES
KW - HEAT-PRODUCTION
KW - ION CHANNELS
KW - NERVE
KW - THERMODYNAMICS
U2 - 10.1016/j.bbamem.2022.184104
DO - 10.1016/j.bbamem.2022.184104
M3 - Journal article
C2 - 36642342
VL - 1865
JO - B B A - Biomembranes
JF - B B A - Biomembranes
SN - 0005-2736
IS - 3
M1 - 184104
ER -
ID: 352034434