Purification and properties of streptococcal nicotinamide adenine dinucleotide glycohydrolase

Highly purified nicotinamide adenine dinucleotide glycohydrolase (NADase) from Steptococcus pyogenes (group A) was obtained by utilizing disodium tetrathionate to protect the enzyme by blocking the sulfhydryl groups of steptococcal proteinase. This was followed by 2 step ion exchange chromatography. The pure enzyme, demonstrated as a single band on sodium dodecyl sulfate/polyacrylamide gel electrophoresis, had a specific activity of 11,200 NADase units per mg of protein and was devoid of hemolytic activity. NADase had a molecular weight of about 55,000 as determined by gel filtration, by summation of amino acid residues, and by sodium dodecyl sulfate/gel electrophoresis. The purified enzyme had optimal activity at pH 7.3 and at 40 C and a calculated K(m) of 5.1 x 10^-4 mM. It was inhibited by α iodoacetamide.