article 4 diethylaminoethyl cellulose enzyme activity 4 enzyme purification 4 nonhuman 4 4 dimethylaminobenzaldehyde 2 Animals 2 Ciliophora 2 Culture Media 2 Liposomes 2 Phaseolus (angiosperm) 2 Phospholipases A 2 Porphobilinogen 2 Porphobilinogen deaminase 2 Protozoa 2 Saccharomyces cerevisiae 2 Substrate-enzyme complexes 2 Tetrahymena thermophila 2 benzylsulfonyl fluoride 2 calcium chloride 2 centrifugation 2 enzyme substrate complex 2 ion exchange chromatography 2 liposome 2 n,n dimethylformamide 2 phospholipase a1 2 phospholipid 2 polyacrylamide gel electrophoresis 2 porphobilinogen deaminase 2 precipitation 2