Aberrant functioning of serine proteases in inflammatory and carcinogenic processes within the gastrointestinal tract(GIT)has prompted scientists to investigate the potential of serine protease inhibitors,both natural...Aberrant functioning of serine proteases in inflammatory and carcinogenic processes within the gastrointestinal tract(GIT)has prompted scientists to investigate the potential of serine protease inhibitors,both natural and synthetic,as modulators of their proteolytic activities.Protease inhibitors of the Bowman-Birk type,a major protease inhibitor family in legume seeds,which inhibit potently and specifically trypsin-and chymotrypsin-like proteases,are currently being investigated as colorectal chemopreventive agents.Physiologically relevant amounts of Bowman-Birk inhibitors(BBI)can reach the large intestine in active form due to their extraordinary resistance to extreme conditions within the GIT.Studies in animal models have proven that dietary BBI from several legume sources,including soybean,pea,lentil and chickpea,can prevent or suppress carcinogenic and inflammatory processes within the GIT.Although the therapeutic targets and the action mechanism of BBI have not yet been elucidated,the emerging evidence suggests that BBI exert their preventive properties via protease inhibition;in this sense,serine proteases should be considered as primary targets in early stages of carcinogenesis.The validation of candidate serine proteases as therapeutic targets together with the identification,within the wide array of natural BBI variants,of the most potent and specific protease inhibitors,are necessary to better understand the potential of this protein family as colorectal chemopreventive agents.展开更多
The WIP1-2 gene was cloned from rice. It be-longs to the Bowman-Birk inhibitor gene family. Northern blot showed that expression of this gene was induced by wounding and jasmonic acid (JA). It indicates that the OsWIP...The WIP1-2 gene was cloned from rice. It be-longs to the Bowman-Birk inhibitor gene family. Northern blot showed that expression of this gene was induced by wounding and jasmonic acid (JA). It indicates that the OsWIP1 gene plays an important role in the rice defense sys-tem. The OsWIP1-2 was cloned into pET28a and expressed in E. coli. Its expressed product was purified in the form of fusion protein and tested for the inhibitory activities against trypsin and chymotrypsin. It was found that the fusion pro-tein could inhibit chymotrypsin, but not trypsin. It was also found that the His tag at its C-terminal affected its inhibitory activity significantly. The fusion protein with a natural C-terminal had the inhibitory activity, while no inhibitory activity was detected in the fusion protein with a (His)6-tag at its C-terminal. This implies that extra amino acid residues at the C-terminal of OsWIP1-2 may interfere with its correct folding. The inhibitory assay indicated that the members of rice Bowman-Birk inhibitor gene family probably differenti-ated both in their structure and function.展开更多
基金Supported by ERDF-co-financed grant from the Spanish CICYT,No.AGL2011-26353 to Clemente AClemente A involved in COST Action FA1005 INFOGEST on Food Digestion
文摘Aberrant functioning of serine proteases in inflammatory and carcinogenic processes within the gastrointestinal tract(GIT)has prompted scientists to investigate the potential of serine protease inhibitors,both natural and synthetic,as modulators of their proteolytic activities.Protease inhibitors of the Bowman-Birk type,a major protease inhibitor family in legume seeds,which inhibit potently and specifically trypsin-and chymotrypsin-like proteases,are currently being investigated as colorectal chemopreventive agents.Physiologically relevant amounts of Bowman-Birk inhibitors(BBI)can reach the large intestine in active form due to their extraordinary resistance to extreme conditions within the GIT.Studies in animal models have proven that dietary BBI from several legume sources,including soybean,pea,lentil and chickpea,can prevent or suppress carcinogenic and inflammatory processes within the GIT.Although the therapeutic targets and the action mechanism of BBI have not yet been elucidated,the emerging evidence suggests that BBI exert their preventive properties via protease inhibition;in this sense,serine proteases should be considered as primary targets in early stages of carcinogenesis.The validation of candidate serine proteases as therapeutic targets together with the identification,within the wide array of natural BBI variants,of the most potent and specific protease inhibitors,are necessary to better understand the potential of this protein family as colorectal chemopreventive agents.
文摘The WIP1-2 gene was cloned from rice. It be-longs to the Bowman-Birk inhibitor gene family. Northern blot showed that expression of this gene was induced by wounding and jasmonic acid (JA). It indicates that the OsWIP1 gene plays an important role in the rice defense sys-tem. The OsWIP1-2 was cloned into pET28a and expressed in E. coli. Its expressed product was purified in the form of fusion protein and tested for the inhibitory activities against trypsin and chymotrypsin. It was found that the fusion pro-tein could inhibit chymotrypsin, but not trypsin. It was also found that the His tag at its C-terminal affected its inhibitory activity significantly. The fusion protein with a natural C-terminal had the inhibitory activity, while no inhibitory activity was detected in the fusion protein with a (His)6-tag at its C-terminal. This implies that extra amino acid residues at the C-terminal of OsWIP1-2 may interfere with its correct folding. The inhibitory assay indicated that the members of rice Bowman-Birk inhibitor gene family probably differenti-ated both in their structure and function.
