SOME CHARACTERISTICS OF STREPTOCOCCAL NICOTINAMIDE ADENINE DINUCLEOTIDASE AND STREPTOLYSIN O.

Pentz, E. Irene (Northwestern University School of Medicine, Chicago, Ill.), Eva Kot, and J. J. Ferretti. Some characteristics of streptococcal nicotinamide adenine dinucleotidase and streptolysin O. J. Bacteriol. 88:497-508. 1964.-Nicotinamide adenine dinucleotidase produced by Streptococcus pyogenes strain C203U, grown in Todd-Hewitt broth (Difco), was recovered from diethylaminoethyl-cellulose columns free from streptolysin O. It contained a trace of deoxyribonuclease. The elution peak of nicotinamide adenine dinucleotidase was fairly symmetrical; when it was treated with dinitrofluorobenzene (DNFB) and chromatogrammed on paper in three different solvent systems, only one yellow spot was obtained. Examination of the enzyme in an ultracentrifuge presented no moving boundary. The pore size of two different widths of Visking casing was estimated by dialyzing proteins or peptides of known molecular weight and testing the dialysate for their appearance. The casing which allowed a molecule of 2,500 molecular weight to pass, but not one of 3,000 molecular weight, retained the nicotinamide adenine dinucleotidase. A fragment having no nicotinamide adenine dinucleotidase activity did pass through this casing, however, but was retained by the second casing which retained molecules weighing 2,500. Amino acid analyses of three different nicotinamide adenine dinucleotidase preparations were remarkably similar, and were characterized by a high content of proline and glycine and a very low content of sulfur-containing amino acids. Examination by treatment with DNFB followed by hydrolysis for the presence of N-terminal amino acids ruled out all amino acids, with the possible exception of arginine. The combined evidence suggests that its molecular weight is between 2,500 and 20,000. Some data are presented to illustrate the irreversible instability of streptolysin O; amino acid analyses for three separate preparations of high activity indicate a very low content of sulfur-containing amino acids.