The flat sheets of the purple membrane from Halobacterium halobium contain only a single protein (bacteriorhodopsin) arranged in a hexagonal lattice. After freeze-drying at -80 degrees C (a method that is superior to air-drying), shadowing with tantalum/tungsten, and image processing, structural details on both surfaces are portrayed in the range of 2 nm. One surface is rough and lattice lines ...

Zika virus is shown in cross section at center left. Visible on the periphery are envelope proteins (pink) and membrane proteins (magenta) embedded in a lipid membrane (light purple). Within the interior of the virus, the RNA genome (yellow) is associated with capsid proteins (orange). Two viruses are shown interacting with cell surface receptors (green) and are surrounded by blood plasma prote...

1. The kinetics of processing newly synthesized bacterio-opsin from the non-crystalline state within the brown membrane to the crystalline state within the purple membrane was followed by pulse-chase experiments. 2. Biosynthesis of bacterio-opsin was found to be highly resistant to RNA-synthesis inhibitors like rifampicin and ethidium bromide. In the presence of ethidium bromide, only five prot...