Serine proteinase inhibitors in seeds of Cycas siamensis and other gymnosperms

Proteinase inhibitors have been identified in seeds of two groups of gymnosperms, the economically important conifers and the ancient cycads. Detailed studies of Cycas siamensis seeds showed that inhibitors of chymotrypsin, subtilisin and trypsin are related to Kunitz-type inhibitors. Analyses of EST databases confirmed the presence of related inhibitors in the Cycadales, Coniferales and Ginkgoales.