金沙江干热河谷地区麻疯树单粒种子核糖体失活蛋白含量及其与种子性状的相关性

对金沙江干热河谷地区麻疯树(Jatropha curcas L.)种子中具有抗肿瘤活性的核糖体失活蛋白curcin含量及其生物学性状进行研究。结果表明,用酶联免疫吸附法测定麻疯树单颗种子的curcin含量为0.275～3.183 mg g-1,平均(1.369±0.055)mg g-1。Pearson相关性分析表明:单粒麻疯树种子的curcin含量与种子其他性状的相关性均未达显著水平,但与种子质量、种仁质量及含油量存在一定程度的负相关,而与出仁率和可溶性蛋白含量存在一定的正相关,且与可溶性蛋白含量的正相关系数(0.190)和与含油率的负相关系数(–0.177)较高。这表明可在金沙江干热河谷地区开展高curcin含量麻疯树种质资源收集和选育工作,以及培育高含油量、高curcin含量的双高品种,以提高麻疯树生物燃油产业的综合效益。     

Type 1 ribotoxin-curcin conjugated biogenic gold nanoparticles for a multimodal therapeutic approach towards brain cancer

Background

Gliomas have been termed recurrent cancers due to their highly aggressive nature. Their tendency to infiltrate and metastasize has posed significant roadblocks to in attaining fool proof treatment solutions. An initiative to curb such a scenario was successfully demonstrated in vitro, utilizing a multi-conceptual gold nanoparticle based photo-thermal and drug combination therapy.

Methods

Gold nanoparticles (Au NPs) were synthesized with a highly environmentally benign process. The Au NPs were PEGylated and conjugated with folate and transferrin antibody to achieve a dual targeted nano-formulation directed towards gliomas. Curcin, a type 1 ribosome inactivating protein, was attached to the Au NPs as the drug candidate, and its multifarious toxic aspects analyzed in vitro. NIR photo-thermal properties of the Au nano-conjugates were studied to selectively ablate the glioma cancer colonies.

Results

Highly cyto-compatible, 10–15 nm Au NP conjugates were synthesized with pronounced specificity towards gliomas. Curcin was successfully conjugated to the Au NPs with pH responsive drug release. Prominent toxic aspects of curcin, such as ROS generation, mitochondrial and cytoskeletal destabilization were witnessed. Excellent photo-thermal ablation properties of gold nanoparticles were utilized to completely disrupt the cancer colonies with significant precision.

Conclusion

The multifunctional nanoconjugate projects its competence in imparting complete arrest of the future proliferation or migration of the cancer mass.

General significance

With multifunctionality the essence of nanomedicine in recent years, the present nanoconjugate highlights itself as a viable option for a multimodal treatment option for brain cancers and the like.     

Isolation and Characterization of a Curcin Promoter from <Emphasis Type="Italic">Jatropha curcas</Emphasis> L. and Its Regulation of Gene Expression in Transgenic Tobacco Plants

Ribosome-inactivating proteins (RIPs) represent those proteins that universally depurinate conserved α-sarcin loops of large rRNAs. In this study, a 0.6-kb fragment of a 5′ flanking region preceding a curcin gene, encoding a type I RIP curcin, of Jatropha curcas L. endosperm was cloned, and its regulation of expression of the β-glucuronidase (GUS) reporter gene was investigated in transgenic tobacco. Analysis of GUS activities showed that the 0.6-kb flanking fragment of the curcin gene was sufficient to drive the GUS reporter gene expression in tobacco seed. The activity of this flanking fragment was analyzed at different stages of seed development. Histochemical localization of GUS activity indicated that the promoter was specifically active in the endosperm tissue of the dicotyledonous tobacco embryo. Moreover, this activity was first initiated at the heart-shaped embryonic stage during seed development.     

麻疯树逆境蛋白(curcin 2)基因在烟草中的表达

麻疯树（Jatropha curcas）幼苗在干旱、高低温胁迫和真菌浸染下,其叶片中诱导产生了一种新的毒蛋白curcin 2。这意味着curcin 2在其它植物中的异源表达可能会增强植物对外界胁迫的抵抗。curcin 2 cDNA的两个片断：cur2p片断（编码前成熟蛋白）和cur2m片断（编码成熟蛋白）,通过农杆菌的介导分别转化烟草并获得转基因植株。但是,只有在插入了cur2p片断的烟草中检测到了curcin 2蛋白的表达。同时,curcin 2在烟草中的表达增强了植株对烟草花叶病毒（TMV）的抗性。