title: Freeze-fractured purple membrane particles: protein content.
abstract: Optical diffraction and image reconstruction can be used to correlate the electron microscope image of the biological membrane with its electron density projection. Such correlation shows that a single purple membrane particle contains 9 to 12 protein molecules--63 to 84 transmembrane alpha helices--a complexity two to ten times greater than that previously suggested for membrane particles.
mesh_terms: D001436:Bacteriorhodopsins; D002338:Carotenoids; D005614:Freeze Fracturing; D006217:Halobacterium / Q000648:ultrastructure*; D008565:Membrane Proteins; D011487:Protein Conformation; D014961:X-Ray Diffraction
chemical_list: D008565:Membrane Proteins; D002338:Carotenoids; D001436:Bacteriorhodopsins