Rapid lateral diffusion of phospholipids in rabbit sarcoplasmic reticulum

Phospholipid spin labels incorporated in the sarcoplasmic reticulum from rabbit-skeletal muscle undergo rapid lateral diffusion within the plane of the membrane. The diffusion constant, D, is 6x10(-8) cm(2)/sec at 37 degrees . With this diffusion constant, a phospholipid molecule can diffuse a distance of the order of 5000 nm in 1 sec.