PURIFICATION AND PROPERTIES OF BILE-ACID SULFATE SULFATASE FROM PSEUDOMONAS-TESTOSTERONI

The bile acid sulfate sulfatase (BSS) produced by Pseudomonas testoste roni was purified and characterized. Chromatofocusing behavior and ami no acid sequence over twelve amino acid residues from N-terminus of th e enzyme indicated that BSS was composed of two isoforms of which mole cular weights were 125,000 and 103,000. Each isoform was a homodimer o f a subunit of which molecular weight was 53,000 or 51,000, respective ly. The optimum pH was 8.5 and BSS was stable at pH 5.8-8.0. The therm ostability above 32 degrees C was improved by the addition of polyols, such as sorbitol, sucrose, and glycerol. BSS was a Mn2+-dependent enz yme and contained 1-2 atoms of manganese in its own protein molecule. All 3 alpha-sulfate esters of the bile acids routinely appearing in hu man serum were hydrolyzed by BSS to 3 beta-hydroxyl iso-compounds corr esponding to each bile acid and sulfuric acid. We tentatively named th is novel enzyme BSS (bile acid 3 alpha-sulfate sulfohydrolase).