[48] Synthesis of capsular polymers contaiing polysialic acid in Escherichia coli 07-K1☆☆☆★★★

Publisher Summary This chapter presents a procedure for synthesis of capsular polymers containing polysialic acid in Escherichia coli 07-K11. For enzyme preparation a heavily encapsulated colony of E. coli K-235 is used. Two similar procedures are used for preparation of the membranous STC. Both consist of membrane hybrids composed of inner and outer membranes. In procedure 1, an operationally defined soluble and particulate STC are resolved whereas in procedure 2, both are included in the same fraction. In preparation of undecaprenyl phosphate-depleted sialyltransferase complex delipidation of both the soluble and paniculate STC is carried out by the acetone-butanol procedure at –20 °. Preparation of exogenous acceptors involves 3 H- or U- 14 C-labeled oligo- and polysialic acid. Further, purification of oligosialic acid is carried out on polyacrylamide gel electrophoresis.