Interaction of phospholipids with Ca2+ ions. On the role of the phospholipid head groups.
Neutral phospholipids play an important role in Ca2+ binding to biomembranes, in particular if the membrane carries a net negative surface charge due to charged lipids or proteins. The concentration of Ca2+ ions in the plane of the phospholipid head groups can be enhanced by at least two orders of magnitude compared to bulk solution. Ca2+ binding furthermore changes the orientation of the phospholipid head groups which is accompanied by variations of the local membrane dipole potential of the order of 10(5) V/cm. Such high electric fields could entail conformational changes of membrane-bound proteins and the Ca2(+)-induced reorientation of the lipid dipoles could thus play a regulatory role in membrane function.
Department of Biophysical Chemistry, University of Basel, Switzerland.
J
J
Seelig
D002118:Calcium / Q000378:metabolism*; D008567:Membranes, Artificial; D010743:Phospholipids / Q000378:metabolism* / Q000502:physiology
D008567:Membranes, Artificial; D010743:Phospholipids; D002118:Calcium