Biological properties of streptococcal cell-wall particles. II. Purification by density gradient column electrophoresis.

Schwab, John H. (University of North Carolina, Chapel Hill). Biological properties of streptococcal cell-wall particles. II. Purification by density gradient column electrophoresis. J. Bacteriol. 90:1412-1419. 1965.-Sucrose gradient column electrophoresis was utilized as a preparative method to purify streptococcal cell-wall fragments. Enzyme-treated cell-wall preparations could be resolved into two major fractions. All of the cell-wall material was in the fraction of slower electrophoretic mobility. The latent time between injection and appearance of nodular lesions in rabbit skin was significantly shorter with this fraction, compared with crude material. In addition, the incidence of relapses of the nodular lesion was reduced with this purified preparation. Addition of the faster electrophoretic fraction back to the slower cell wall-containing fraction prolonged the latent time between injection and appearance of nodules, and increased the incidence of relapses. The latent time was directly proportional to the ratio of the two fractions. Antigens of the electrophoretic fast fraction were distinct from the C polysaccharide and mucopeptide antigens of the cell wall.