Porins and specific channels of bacterial outer membranes.

  title={Porins and specific channels of bacterial outer membranes.},
  author={Hiroshi Nikaido},
  journal={Molecular microbiology},
  volume={6 4},
Porins and specific channels both produce water-filled pores that allow the transmembrane diffusion of small solutes, but the latter contain specific ligand-binding sites within the channels. Recent structural studies show that many or most of these proteins exist as beta-barrels with the beta-strands traversing the thickness of the outer membrane. The channels often have diameters in the range of 1 nm, and thus the penetration rates of solutes through porin channels are likely to be affected… CONTINUE READING