Sodium tetrathionate effect on papain purification from different Carica papaya latex crude extracts

Abstract

Papain from latex of Carica papaya was purified up to MALDI TOF mass spectrometry homogeinity by salt precipitation from two different crude extract sources: a refined preparation obtained in our laboratory and a commercial one. Sodium tetrathionate was tested in the purification process to preserve the enzymatic activity of the peptidase. Purification was checked by SDS PAGE and cation exchange chromatography, using commercial pure papain as standard for a rapid comparison. The best purification yields (3.4 %) were obtained in presence of 30 mM sodium tetrathionate for the crude extract prepared in our laboratory. The described purification method proved to be robust and reliable to obtain pure papain in a preparative scale.