A method for the preparation of Tetrahymena thermophila phospholipase A1 suitable for large-scale production

A rapid and economical method for the purification of phospholipase A(1) (PLA(1)) from the extracellular medium of the ciliate Tetrahymena thermophila is presented. Essentially, the procedure, here designated as purification by selective interaction (PSI), entails the incubation of media containing PLA(1), with liposomes made of soy bean phospholipids. The PLA(1)-lipid complexes are precipitated by the addition of CaCl2 and collected by centrifugation, Elution of the PLA(1), is effected by treating the complexes with 40% dimethylformamide, a reversible inhibitor of this enzyme, which is easily removed by dialysis. In combination with DEAE cellulose ion exchange chromatography, PSI yielded homogeneous PLA(1) preparations with a 14% recovery and a 416-fold increase in specific activity. This procedure, which can be completed within 1 day mag prove useful for the isolation of phospholipases from other sources. This practical method for the purification of a microbial PLA(1) opens the way to large-scale production of these types of enzyme, which are not as yet commercially available.