Dissociation and Reassociation of Bacterial Membrane Components

The dissociation of the phospholipid, lipopolysaccharide, and protein components of the bacterial cell envelope results in loss of enzyme activities which are normally located in the cell envelope structure and which are involved in lipopolysaccharide biosynthesis. The activity of one of these enzymes, UDP-galactose:lipopolysaccharide α,3 galactosyl transferase, can be restored by the reassociation of purified phospholipid, lipopolysaccharide, and enzyme protein. Reconstitution of activity occurs in stepwise fashion: lipopolysaccharide + phospholipid → lipopolysaccharide·phospholipid See PDF for Equation enzyme·lipopolysaccharide·phospholipid. The intermediates in the reaction were isolated by gradient centrifugation. The final ternary complex behaves in a similar manner to the intact cell envelope in the enzyme reaction and appears to represent the reconstitution of a portion of the membranous portion of the cell envelope.