Labelling of the integral proteins of sarcoplasmic-reticulum membranes.

Photoreactive lipids were introduced into rabbit and rat sarcoplasmic-reticulum membranes to label specifically integral proteins. Evidence was obtained that, in addition to the Ca2+-dependent ATPase, the 160 000-Mr glycoprotein, the 53 000-56 000-Mr components and polypeptides of Mr 30 000, 20 000 and 6000 are integral components of sarcoplasmic-reticulum membranes.