The minor anionic form of arylsulphatase B (arylsulphatase Bm) of monkey brain. Purification and phosphoprotein nature

Abstract

The anionic form of arylsulphatase B (arylsulphatase Bm) was purified to apparent homogeneity from monkey brain through steps involving chromatography on diethylaminoethyl-cellulose, Blue-Sepharose, Biogel HTP and finally Biogel P-300 gel filtration. The molecular weight of the purified enzyme as deduced by gel filtration on Biogel P- 300 and by sodium dodecylsulphate gel electrophoresis was ~ 30,000. Escherichia coli alkaline phosphatase treatment of arylsulphatase Bm resulted in the conversion of upto 84% of the enzyme into a less charged form of enzyme, that could not bind to diethylaminoethyl cellulose. Potassium phosphate an inhibitor of alkaline phosphatase prevented this conversion. Upon acid hydrolysis the purified enzyme yielded approximately 7.0 mol of inorganic phosphate per mol of protein. Vibrio cholerae neuraminidase treatment did not alter the charge on arylsulphatase Bm.