Purification and Some Properties of Water-soluble Phospholipase B from Torulaspora delbrueckii(Biological Chemistry)

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Water-soluble phospholipase B was purified to homogeneity from Torulaspora delbrueckii cell washings. The washings were concentrated by ultrafiltration, and then a fraction with phospholipase B activity was precipitated with ammonium sulfate, and purified by sequential column chromatographies on Octyl-Sepharose CL-4B, DEAE-Sephacel, and Spharose 6B. The molecular weight of the enzyme was setimated to be 170,000〜200,000 by SDS-polyacrylamide gel electrophoresis and by gel filtration with a Sephadex G-200 column. The isoelectric point of the enzyme was 4.0. The purified enzyme had two pH optima at pH 2.5 and pH 7.5. The activity at acidic pH was greatly stimulated by the divalent metal ions tested, but the activity at alkaline pH was stimulated mainly by Ca^<2+> and Fe^<2+>. The purified enzyme had both lysophospholipase activity and phospholipase B activity in a ratio of 37 : 1 at acidic pH adn 73 : 1 at alkaline pH. The amino acid composition of the enzyme was characterized by high contentsof Asp, Ser, Leu, and Gly.
社団法人日本農芸化学会の論文
1988-10-23