CYSTEINE PROTEASE ACTIVITY IN ARILS OF THAUMATOCOCCUS-DANIELLII - RELATIONSHIP BETWEEN THE SWEET PROTEIN THAUMATIN AND CYSTEINE PROTEASE ACTIVITY

1. The intensely sweet protein thaumatin was originally reported to po ssess autolytic activity, manifest only in the presence of reducing ag ents. We have shown that the proteolytic activity in partially purifie d thaumatin preparations is attributable to a cysteine proteinase, tha umatopain, that can be separated from thaumatin by cation exchange chr omatography. 2. Lesser peaks of proteolytic activity coeluted with tha umatin variants, which did not completely exclude the possibility of a weak but inherent proteolytic activity in the thaumatins. 3. The mino r proteolytic peaks were resolved from thaumatins by hydrophobic inter action chromatography, and are probably due to minor charge Variants o f the thaumatopains. Thaumatin has no intrinsic proteolytic activity.