Further studies on the properties of violet-colored acid phosphatase from soybean.

Abstract

The properties of the acid phosphatase isolated in a homogeneous state from soybean (Glycine max) have been investigated in detail. The enzyme catalyzed the hydrolysis of a wide variety of phospholylated compounds including phosphomonoesters, nucleotide mono-, di-and triphosphate, and inorganic pyrophosphate. No activity was detected for nicotinamide adenine dinucleotide and diphenyl phosphate. The enzyme activity was inhibited by orthophosphate, arsenate, fluoride, molybdate, and heavy metal ions including Cu²⁺, Zn²⁺, Hg²⁺ and Ag⁺. Treatment of the enzyme with chelating agents, reducing agents and oxidizing agents resulted in inactivation of the enzyme. The reduction of the absorbance at 540 nm of the enzyme was observed in parallel with the loss of the enzyme activity by the treatment with ethylenediaminetetraacetic acid and rongalit, but not with H₂O₂. The enzyme had a molecular weight of approximately 240000. Polyacrylamide disc gel electrophoresis in the presence of sodium dodecyl sulfate suggested that the enzyme dissociated into subunits with molecular weight of approximately 60000. The amino acid and carbohydrate composition of the enzyme were also determined.