A tartrate-resistant acid phosphatase from Gaucher spleen. Purification and properties.

”he acid phosphatase activity that is elevated 3to 5fold in the spleen in Gaucher’s disease can be resolved into two principal isoenzymes by chromatography on sulphopropyl-Sephadex: one tartrate-sensitive component does not bind to the resin whereas the second acid phosphatase, which is tartrate-resistant, binds to the column and can be eluted by a buffer containing 0.4 M sodium chloride. We have isolated and characterized the L-(+)-tartrate-resistant isoenzyme of acid phosphatase (designated SPU) from the spleen of a patient with adult (type 1) Gaucher’s disease. The enzyme represents approximately 50% of the total acid phosphatase activity in a homogenate of spleen prepared in the presence of Triton X-100 and has been purified 24,000-fold by chromatography on columns containing carboxymethylSephadex, hydroxylapatite, Sephadex G-150, and concanavalin A-Sepharose. The specific activity of the final preparation (1490 pmol/min/mg) is one of the highest reported €or an acid phosphatase from a human source. The SPIl acid phosphatase isoenzyme catalyzes the hydrolysis of the artificial substrates I-methylumbelliferyl phosphate and p-nitrophenyl phosphate, as well as nucleoside tri and diphosphates. The Gaucher spleen acid phosphatase also catalyzes the dephosphorylation of phosvitin and erythrocyte membrane phosphoproteins including spectrin. The enzyme is inhibited by molybdate (&, 0.002 m ~ ) , cupric ion, fluoride (Kj , 1.0 mM), dithionite (Ki, 0.5 mM), and ferrous ion (Ki, 1.5 mM). The enzyme has the following properties: 1) pH optimum, 5.5; 2) K,, 0.90 m~ on 4-methylumbelliferyl phosphate; 3) PI, 8.5; 4) S Z ~ , ~ , 3.3; 5 ) Mr = 33,000.