Bowman-Birk inhibitors (BBIs) are small double headed protease inhibitors targeting trypsin and chymotrypsin; small changes in the active loop can modify specificity to other proteases. They are antinutritionals affecting animal digestion and health. They also play a role in defence of plants against the attacks by insects, pathogens and other predators. Recent studies are now proposing a possible role of the chymotrypsyn active site in controlling cancer cell proliferation. Two paralogous BBI genes have been isolated in lentil. The relative proteins retain a high level of similarity to the pea TI1 and TI6 peptides. In fact, one class (TI1-like) shows the presence of a trypsin and a chymotrypsin active site, the other one (TI6-like) displays two trypsin sites. However, some important differences in the active site loop are present in lentil as compared to pea. The expression pattern of the two lentil BBI classes was evaluated by means of Real Time PCR, using cDNA synthesised from leaf, root and seed RNA. Results show that TI1-like class is preferentially expressed in seeds, while TI6-like one displays a higher level of expression in leaves. Since only the TI-1 like polypeptide contains the chymotrypsin active loop, seeds could provide extracts enriched with this protein to be possibly used in pharmaceutical applications. At the same time, the expression of its coding gene is being performed in appropriate vectors, in order to obtain purified proteins to be employed in bioassays.
Lentil BBI coding genes: a door for new plant products?
Sonnante G;Pignone D
2006
Abstract
Bowman-Birk inhibitors (BBIs) are small double headed protease inhibitors targeting trypsin and chymotrypsin; small changes in the active loop can modify specificity to other proteases. They are antinutritionals affecting animal digestion and health. They also play a role in defence of plants against the attacks by insects, pathogens and other predators. Recent studies are now proposing a possible role of the chymotrypsyn active site in controlling cancer cell proliferation. Two paralogous BBI genes have been isolated in lentil. The relative proteins retain a high level of similarity to the pea TI1 and TI6 peptides. In fact, one class (TI1-like) shows the presence of a trypsin and a chymotrypsin active site, the other one (TI6-like) displays two trypsin sites. However, some important differences in the active site loop are present in lentil as compared to pea. The expression pattern of the two lentil BBI classes was evaluated by means of Real Time PCR, using cDNA synthesised from leaf, root and seed RNA. Results show that TI1-like class is preferentially expressed in seeds, while TI6-like one displays a higher level of expression in leaves. Since only the TI-1 like polypeptide contains the chymotrypsin active loop, seeds could provide extracts enriched with this protein to be possibly used in pharmaceutical applications. At the same time, the expression of its coding gene is being performed in appropriate vectors, in order to obtain purified proteins to be employed in bioassays.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
