Isolation and characterization from potato tubers of two polypeptide inhibitors of serine proteinases

Effect of trypsin inhibitor from Crotalaria pallida seeds on Callosobruchus maculatus (cowpea weevil) and Ceratitis capitata (fruit fly)

“…Proteinaceous inhibitors have been purified and characterized from a variety of plant sources [30][31][32][33][34][35]. The role of these inhibitors as defensive compounds against predators was studied as early as 1947 when Mickel and Standish [36] observed that larvae of certain insects were unable to develop on soybean products.…”

“…On the basis of the concentration (1-10% of total protein) of proteinaceous inhibitors that occur naturally in legume seeds [60,61], the potential bioinsecticidal effects of CpaTI at 1-4% doses (w/w) were tested in feeding trial models for C. capitata and C. maculatus larvae, two important and economical pests in tropical and subtropical regions. Results showed deleterious effects of CpaTI on the growth and survival of C. capitata and C. maculatus during larval development.…”

Posttranslational Modification of an Isoinhibitor from the Potato Proteinase Inhibitor II Gene Family in Transgenic Tobacco Yields a Peptide with Homology to Potato Chymotrypsin Inhibitor I

“…As well as representatives of the PPI-I and PPI-I1 gene families, an additional class of proteinase inhibitory peptides has also been purified from potato (Pearce et al, 1982). These are lower molecular mass proteins that contain only proteinase reactive site and inhibit either trypsin (designated potato trypsin inhibitor I) or chymotrypsin (PCI-I).…”

Trypsin-specific inhibitors from the basidiomycete Clitocybe nebularis with regulatory and defensive functions

“…Analogously to plants, in which protease inhibitors play an important defensive role (Habib & Fazili, 2007), serine protease inhibitors probably play a defensive role against predation by insect pests and different pathogens also in mushrooms. The insecticidal effect of CnSPIs was compared with those of three plant serine protease inhibitors: PSPI and PI2, two serine protease inhibitors from potato (Brzin et al, 1995;Pearce et al, 1982), and CMTI, a trypsin inhibitor from pumpkin (Krishnamoorthi et al, 1990). The CnSPIs showed an effect similar to that of PSPI, PI2 left no surviving larvae, whereas CMTI had no effect.…”

“…Rearing medium containing 0.5 mg BSA ml 21 was used as a reference assay. The following protease inhibitors were tested at a final concentration of 0.5 mg ml 21 : C. nebularis serine protease inhibitors (CnSPIs), serine protease inhibitor from pumpkin, Cucurbita maxima (CMTI) (Krishnamoorthi et al, 1990), potato serine protease inhibitor (PSPI) (Brzin et al, 1995), potato protease inhibitor 2 (PI2) (Pearce et al, 1982), and C. nebularis cysteine protease inhibitor (clitocypin) (Brzin et al, 2000). Relative mortality (RM) of larvae was determined as RM512[(test mortality)/(reference mortality)] and standard deviation was calculated.…”