87] Preparation and properties of acetyl phosphatase

Abstract

Publisher Summary This chapter discusses the preparation and properties of acetyl phosphatase. In the course of preparation, ground horse meat (2.5 kg.) is added to 7.5 l. of boiling 1% KCl-0.067 M HCl (final pH ca. 3.0). After 10 minutes, the solution is cooled to room temperature as rapidly as possible, and the mixture is filtered through cheesecloth. The filtrate is neutralized to pH 6 with 1 M sodium bicarbonate, and the precipitate which forms is removed by centrifugation. The purification follows the procedure of Lipmann and is based on the stability of acetyl phosphatase in the presence of such strong denaturing agents as hot acidic solutions and cold trichloroacetic acid. The various properties of the enzyme discussed are: (1) the enzyme is nondialyzable and is destroyed by pepsin, (2) it is resistant to hot acidic (pH 3) solutions and to cold trichloroacetic acid, (3) it is presumed to be a basic protein because of its solubility in acidic, and its insolubility in basic, solutions, (4) the enzyme is present in a wide variety of animal tissues and to a smaller extent in bacteria, and (5) the enzyme is inhibited strongly by phosphate, pyrophosphate, hexosephosphate, nucleic acid, and hyaluronic acid, etc.