[Inhibition of cathepsins from trout muscle and from bovine spleen by proteinase inhibitors of potato tubers (author's transl)].

The cathepsins D from trout muscle and from bovine spleen, as well as cathepsin A from bovine spleen are inhibited by a crude proteinase inhibitor from potato tubers. Cathepsins C and B1 are not inhibited. It was shown by isoelectric focussing that several inhibitors for cathepsin D are present in potatoes. Those with isoelectric points at pH 9.2, 9.1, 9.0, 8.9, 8.5 inhibit cathepsins D both from trout muscle and from bovine spleen. In addition some inhibitors with isoelectric points at pH 6.6, 6.5, and 6.2 were observed, which inhibit cathepsin D from trout muscle only.