Synthesis of capsular polysaccharide (hyaluronic acid) by protoplastmembrane preparations of group A Streptococcus.

Previous reports from this laboratory demonstrated the synthesis of hyaluronic acid by a cell-free preparation obtained from a strain of Group A streptococcus. The enzymic activity which sedimented at 105,000 x g, but not at 10,000 x g, required the addition of uridine diphospho-N-acetylglucosamine, uridine diphosphoglucuronic acid, and Mg++ for the formation of hyaluronic acid (l-3). Since hyaluronic acid occurs in the capsule of streptococci, this system affords an opportunity for the localization of synthesis of a high molecular weight polymer found external to the cell. The availability of “phage-associated lysin” capable of solubilizing the cell wall of Group A streptococcus (4) facilitated the preparation (5) of protoplast membranes used in this study. This paper reports the synthesis of hyaluronic acid by protoplast membrane preparations that are relatively free of nucleic acids and cell wall material. A preliminary report of this work has appeared (6). Additional information regarding the properties of the hyaluronic acid-synthesizing system is presented.