JACQUET A, KLEINSCHMIDT T, SCHNEK AG, LOOZE Y, BRAUNITZER G. The Thiol Proteinases from the Latex ofCarica papayaL. III. The Primary Structure of Chymopapain. Biological Chemistry Hoppe-Seyler. 1989 Jan;370(1):425–34. doi: 10.1515/bchm3.1989.370.1.425.