Phytohemagglutinin and transmembrane proteins in agglutinated sheep erythrocyte ghost membranes

Oriented and periodically stacked sheep erythrocyte ghost membrane specimens were prepared by agglutination of the ghosts with phytohemagglutinin M and sedimentation, and were studied by X-ray diffraction. The spatial orientation of the planes of the membranes in the diffracting stack was determined from the lamellar reflections of the periodic stacking. Equatorial diffraction at (10.5 A)-1 and a (1.5 A)-1 reflection were recorded which correlate with side-to-side packed transmenbrane alpha-helices in the agglutinated membrane. A broad (4.6 A)-1 ring with strong equatorial accentuation and broad maxima at about (2.2 A)-1 and (1.2 A)-1 were observed which are attributed to the hydrocarbon chain arrangement in lipid phases of the agglutinated ghost membrane.