Orientation of the cell membrane in ghosts and electron transport particles of Mycobacterium phlei.

The chemical and enzymatic composition and the respiratory components of an intact membrane preparation, ghosts from Mycobacterium phlei, were compared to those of the electron transport particles. The ghosts were found to contain 5 to 7% of some of the soluble enzymes associated with the cytoplasm. In contrast, 97% of the total content of cytochromes b, cl + c, and a + a3 was found in the ghost preparation. The content of cytochromes, menaquinone, latent ATPase, and phospholipid was similar in both ghost and electron transport particle preparations. The oxidative activities of the ghosts were similar to or slightly lower than those of the electron transport particles with all substrates tested. Coupled phosphorylation, however, was cryptic with the ghost preparations. Phosphorylation was demonstrable following brief sonication or preincubation of the ghosts with substrates and other components of the phosphate acceptor system. The synthesis of ATP was found to occur within the ghosts. Evidence is presented which suggests that the cell membrane of the ghost is oriented as in the intact cell, whereas the orientation of the membrane in the electron transport particles appears to be inside out.