Curcin, a ribosome-inactivating protein with a molecular weight of about 28.2 kD, which strongly inhibits the protein synthesis in rabbit reticulocyte lysate system with an IC50 value of about (0.19 +/- 0.01) nmol/L, ...Curcin, a ribosome-inactivating protein with a molecular weight of about 28.2 kD, which strongly inhibits the protein synthesis in rabbit reticulocyte lysate system with an IC50 value of about (0.19 +/- 0.01) nmol/L, was purified from the seeds of Jatropha curcas L. The protein has the activity of rRNA N-glycosidase. Degenerate primers were designed based on the N-terminal partial sequence from purified curcin. The full-length curcin cDNA by RT-PCR and 5'-RACE was cloned. The deduced amino acids sequence indicates that a preprotein with 20 amino acid residues is first translated and then processed to a mature protein with 251 amino acids. The deduced amino acids sequence shares homology of 33% and 57% to those of type I ribosome-inactivating proteins (RIPs) and A chain of type II RIPs, respectively. The sequence encoding mature curcin was integrated into the pQE-30 vector for expression in Escherichia coli strain M15 (pREP4). The purified recombinant curcin was able to inhibit protein synthesis in rabbit reticulocyte lysate system.展开更多
The proteins from endosperm, root, stem, leaf, leafstalk of Jatropha curcas L. and their calli were hybridized to the seed toxin protein (curcin) of Jatropha curcas L. by western blot. The result showed that the curci...The proteins from endosperm, root, stem, leaf, leafstalk of Jatropha curcas L. and their calli were hybridized to the seed toxin protein (curcin) of Jatropha curcas L. by western blot. The result showed that the curcin was specifically expressed in the endosperm and its calli, while it was not detected in root, stem, leaf, and leafstalk of Jatropha curcas L. and their calli . This study indicated that calli induced from endosperm can be used to produce curcin.展开更多
文摘Curcin, a ribosome-inactivating protein with a molecular weight of about 28.2 kD, which strongly inhibits the protein synthesis in rabbit reticulocyte lysate system with an IC50 value of about (0.19 +/- 0.01) nmol/L, was purified from the seeds of Jatropha curcas L. The protein has the activity of rRNA N-glycosidase. Degenerate primers were designed based on the N-terminal partial sequence from purified curcin. The full-length curcin cDNA by RT-PCR and 5'-RACE was cloned. The deduced amino acids sequence indicates that a preprotein with 20 amino acid residues is first translated and then processed to a mature protein with 251 amino acids. The deduced amino acids sequence shares homology of 33% and 57% to those of type I ribosome-inactivating proteins (RIPs) and A chain of type II RIPs, respectively. The sequence encoding mature curcin was integrated into the pQE-30 vector for expression in Escherichia coli strain M15 (pREP4). The purified recombinant curcin was able to inhibit protein synthesis in rabbit reticulocyte lysate system.
文摘The proteins from endosperm, root, stem, leaf, leafstalk of Jatropha curcas L. and their calli were hybridized to the seed toxin protein (curcin) of Jatropha curcas L. by western blot. The result showed that the curcin was specifically expressed in the endosperm and its calli, while it was not detected in root, stem, leaf, and leafstalk of Jatropha curcas L. and their calli . This study indicated that calli induced from endosperm can be used to produce curcin.
