The outer membranes of Gram-negative bacteria are size dependent molecular sieves. Permeation of hydrophilic molecules below a certain exclusion limit occurs through the water-filled channels of a class of proteins called porins. Porins control the influx of nutrients and the efflux of metabolites and constitute a permeation barrier against certain antibiotics and other noxious chemicals. They protect pathogenic organisms from host defence factors. Porins are now well understood due to their relative ease of purification and subsequent examination in model membrane systems.
|Number of pages
|Today's Life Science
|Published - 1 Jan 1992
- Bacterial Outer Membrane Proteins
- Gram-Negative Bacteria