Chromatographic separation of two acid phosphatases from rat bone

Abstract

Extracts of tibiae of suckling rats were prepared with 0.3 M KCl containing 0.1% Triton X-100 and were chromatographed with CM-52 cellulose. Most of the acid phosphatase activity determined with p-nitrophenylphosphate (p-NPP) was bound to the cellulose and could be eluted with a sodium acetate buffer gradient in 2 distinct peaks. The major peak, E₂, was bound strongly to the cellulose and showed high activity with p-NPP and inorganic pyrophosphate (P-P_i), but only slight activity withβ-glycerophosphate (β-GP) and was unaffected by tartrate. The minor peak, E₁, was weakly bound to the adsorbent, showed equal activity with p-NPP andβ-GP, but negligible activity with P-P_i and was completely inhibited by tartrate. These results support earlier evidence suggesting that bone contains at least 2 different acid phosphatases and that the more abundant enzyme may function as a pyrophosphatase.