Biotechnological applications of protein hydrolysates and curcin from Jatropha Curcas L seeds

The extraction of oil from Jatropha curcas seeds for the production of biodiesel generates a protein-rich seed cake like by-product. The main protein fractions are globulin, glutelin and curcin, an albumin that is characteristic of this species. This composition facilitates the use of this plant for biotechnological applications of its proteins. In fact, the protein isolates from J. curcas are a good substrate for the production of hydrolysates with improved functional and nutritional properties. The peptides released upon enzymatic hydrolysis of J. curcas seeds have higher antioxidant and iron-chelating activity than the original hydrolysates. Several functional proteins and cyclic peptides with important biological activities, since plant protection until pharmaceutical properties, have been isolated from Jatropha curcas. Among them, curcin and curcacycline have shown potential toxicity against tumor cells, antimalarial activity, and inhibition of the classical activation pathway of human complement and the proliferation of human T-cells. In fact, cell lines exposed to curcin exhibited significant metabolic arrest by several mechanisms in a dose-dependent manner. The protein has been conjugated to nanoparticles or antibodies in order to enhance the targeting and the anti-tumor activity of curcin. Conjugated curcin has shown significant inhibitory effects on the proliferation of cancer cell lines that over-express the target receptor and had less of an inhibitory effect on cells with lower levels of target receptor expression. In this way, the conjugates open up the possibility of using this ribotoxin as a therapeutic against cancers of diverse origins. It is expected that the information collated will open avenues for new applications of the proteins in the J. curcas plant, thereby enhancing the financial viability and sustainability of a Jatropha-based biodiesel industry.