Abstract
Pineapple stem bromelain has been successfully isolated from an acetone powder of a crude plant extract by a single passage through a column of ∊-aminocaproyl-D-tryptophan methyl ester coupled to Sepharose 4B. If organic mercury is present during all steps of the procedure, a single band with an apparent molecular weight of 23, 000 daltons is obtained after gel electrophoresis in 1% sodium dodecyl sulfate. Upon reduction with mercaptoethanol, this single species is converted into two chains of about 15, 000 and 8, 500 daltons.