A NOVEL PROTEINASE AND ITS SPECIFIC PROTEIN-INHIBITOR IN SPINACIA-OLERACEA LEAF

A novel proteinase has been evidenced in spinach (Spinacia oleracea L. ) leaves. Substrate and inhibitor specificities of the purified enzyme indicate that this proteinase is different from the previously descri bed proteinase which displays a peculiar leucine specificity. A protei nase protein-inhibitor has been evidenced in the same extract, along w ith the already described anti-trypsin inhibitor. This novel protein-i nhibitor has no activity against trypsin while it is effective against the proteinase described here. Furthermore, the observed inhibition s hows ionic strength dependence, a characteristic common to many plant proteinase/specific inhibitor systems. (C) Elsevier, Paris.