The Role of Membranes in the Transport of Small Molecules
An understanding of the dependencies of transmembrane solute transport systems on the phospholipid matrix ultimately depends on a thorough knowledge of the detailed structural and functional properties of the proteins which catalyze vectorial reactions. This chapter selectively deals with subjects which the authors believe provide mechanistic insight into the selective permeability properties of the Gram-negative bacterial cell envelope. It also deals with frequent reference to original research articles and reviews to provide the reader with opportunity for more detailed analyses of subjects. The chapter concentrates on mechanisms of transmembrane solute translocation in bacteria and on functionally important interactions of the permease proteins with the matrix phospholipids. It discusses that the activities of a variety of permeases specific for sugars, amino acids, and protons are dependent both on the fatty acid and phospholipid composition of the membrane.