PURIFICATION OF ACID-PHOSPHATASE-I FROM GERMINATING-SEEDS OF VIGNA-SINENSIS

Acid phosphatase I(AP-I) is the major isoform of Vigna acid phosphatas e. It is constitutively expressed in seed cotyledons during germinatio n. AP-I was separated from other isoforms and purified to homogeneity by three simple purification steps; (NH4)(2)SO4 precipitation, and pho sphocellulose and DEAE-cellulose column chromatography. The activity o f AP-I was not affected by 1 mM Mg2+, Mn2+, Ca2+, Co2+ or Pb2+, but se verely inhibited by 1 mM Cu2+, Fe3+, Hg2+, Mo6+ or Zn2+. AP-I has both phosphatase and pyrophosphatase activities, and is highly stable even at 50 degrees.