Abstract
Certain strains of Streptococcus pyogenes, Type 12 elaborate a polypeptide which is nephritogenic in experimental animals. It appeared to be a pure, nonmigrating component by paper chromatography, to be electrophoretically pure when analyzed by the Spinco electrophoretic system, and to be homogeneous by ultracentrifugal analysis. Quantitative amino acid analyses of acid-hydrolyzed samples revealed 19 amino acids and trace amounts of five unidentified components. Glycine, proline, alanine, glutamic acid and aspartic acid accounted for 70% of the amino acids found. Wilzbach tritiated samples were injected intraperitoneally into 20-g C57B1 male mice. Radioautographic evidence revealed that a high percentage of the injected material concentrated in renal tissue.