Dekeyser P M, De Smedt S, Demeester J, Lauwers A
Department of Pharmaceutics, University of Ghent, Belgium.
J Chromatogr B Biomed Appl. 1994 Jun 3;656(1):203-8. doi: 10.1016/0378-4347(94)00083-2.
Three cysteine proteinases, i.e. chymopapain, papaya proteinase IV and proteinase III, were purified to homogeneity from papaya latex using a combination of ion-exchange chromatography and hydrophobic interaction chromatography. During the purification procedure, the thiol-groups of the active center were reversibly blocked as mixed disulfides with 2-thiopyridone. Homogeneity was proved electrophoretically by native polyacrylamide gel electrophoresis (PAGE), sodium dodecyl sulfate (SDS)-PAGE and rechromatography on a Mono S 5/5 column at pH 5.0.
