Expression and Activity of Pre-dianthin 30 and Dianthin 30

Dianthin 30 is a ribosome inactivating protein (RIP 1) found in different tissues of the carnation ( Dianthus caryophyilus). Recently we have isolated and sequenced a cDNA clone from a λgt11 expression library [Legname et al. (1991) Biochim. Biophys. Acta 1090, 119-122]. Here we describe specific PCR amplifications of either the fill length pre-dianthin 30 or dianthin 30, the mature polypeptide lacking the 23 amino acid signal peptide. In vitro expression of both proteins in reticulocyte lysate generated products of the expected molecular weight. Moreover, the activity of both proteins has been evaluated confirming the characteristics of the natural product. A first attempt to produce recombinant dianthin 30 in Escherichia coli is described.