Preparation of the antibiotic nisin.

myokinase. A disadvantage of the method is the slow hydrolysis of adenosinetriphosphate in the final stages of the reaction. 2. Metallic salts of adenosinetriphosphate are shown to be unstable and break down on storage to adenylic acid and inorganic pyrophospShate, and to a less extent to adenosinediphosphate and inorganic phosphate. 3. The best preparations of adenosinetriphosphate are at least 95% pure. The possibility that some impurity is present is not excluded. 4. The use ofpotato apyrase for the assay ofadenosinetriphosphate is restricted by its contamination with a nucleotidase and an inorganic pyrophosphatase. 5. Both in fresh and in rigor muscle, the adenosinediphosphate present is less than 5% and probably greater than 1 % of the labile nucleotide phosphorus. 6. The claims of Banga concerning the action of muscle enzymes on adenosinetriphosphate are criticized.