Abstract
Phospholipase B from Streptomyces hiroshimensis was purified 220-fold in specific activity by means of acetone treatment, gel filtration on Sephadex G-75 and isoelectric focusing, and the recovery of the activity was 60%. The isoelectric point was found to be around pH 7.3 and the molecular weight was about 15, 000. The phospholipase B had an optimum pH of 9.0. The enzyme retained 80% of the activity when heated for 60min at 37°C. The activity was stimulated by Ca2+, Ba2+ and Triton X-100 and inhibited by Zn2+, Co2+, Fe3+, Al3+ Adekatol SO-120, sodium cholate, sodium deoxycholate, lauryl benzene sulfonate, Cation DT-205 and cetylpyridinium chloride. The enzyme attacked phosphatidylcholine more rapidly than phosphatidylethanolamine. Under the same condition, the enzyme also hydrolyzed the lysophospholipids, lysophosphatidylcholine and lysophosphatidylethanolamine.
