Three serine proteases from the latex of Euphorbia cyparissias

Abstract

Three serine-centred proteolytic enzymes, euphorbains y-1, −2 and −3, were isolated from the latex of Euphorbia cyparissias. These proteases have different specific activities to azocoll and CBZ glycine p-nitrophenyl ester. The pIs and M rs of y-1, −2 and −3 are 5.2 and 67 000, 5.2 and 33 000, and 6.3 and 67 000, respectively. The enzymes, which are glycoproteins, are immunologically distinct from euphorbain 1, but clearly related to that enzyme in amino acid composition.