Fractionation studies of the enzyme complex involved in teichoic acid synthesis

The membrane-bound enzymes participating in the syntheses of the teichoic acid main chain and linkage unit have been solubilized with Triton X-100 and fractionated by sucrose density gradient centrifugation. Two main fractions were obtained: a heavy fraction, containing enzymes effecting synthesis of the main chain attached to the linkage unit, which was associated with only a small amount of lipid, and a light fraction which was rich in prenyl phosphate and catalyzed only linkage-unit synthesis. The separation by density was not based entirely on polypeptide chain length, as some of the shortest chains appeared in the denser fractions and some relatively high-molecular-weight peptides occurred in the lightest fraction. High activity for linkage-unit synthesis was observed in a fraction containing only a few peptides. Addition of ficaprenyl phosphate to the enzyme preparations had no stimulatory effect. It is concluded that the enzymes for main-chain and linkage unit syntheses frm one or more fairly tightly associated complexes and that polyprenyl phosphate is an integral firmly bound component of the complex in which the linkage unit is synthesized.