Assessment of new triplet forming artificial nucleobases as RNA ligands directed towards HCV IRES IIId loop.

We report the synthesis of two new artificial nucleobase scaffolds, 1 and 2, featuring adequate hydrogen bonding donors and acceptors for the molecular recognition of U:A and C:G base pairs, respectively. The tethering of these structures to various amino acids and the assessment of these artificial nucleobase-amino acid conjugates as RNA ligands against a model of HCV IRES IIId domain are also reported. Compound 1e displayed the highest affinity (Kd twice lower than neomycin - control). Moreover, it appears that this interaction is enthalpically and entropically favored.

In vitro transient expression system of latex C-serum was used for analysis of hevein promoter in response to abscisic acid in Hevea brasiliensis.

Hevein has been found to be an essential element in coagulation of rubber particles in latex of rubber trees. In a previous study, we cloned a 1,241-bp fragment of a 5' upstream region of the hevein gene by genome walking. This fragment was analyzed by a 5' end nested deletion method in the present study, fused with a uidA (gus) gene to produce a series of tested constructs, which were transferred into C-serum of latex and the Gus activities were detected. Results showed that the fragment from -749 to -292 was sufficient for expression of gus gene in latex, and the fragment from -292 to -168 was crucial in response to abscisic acid inducement. In a transient transgenic test of rubber leaf with particle bombardment, construct Hev749 conferred gus-specific expression in veins, in which the latex tubes mainly distributed. This implies that the fragment from -749 to -292 was laticiferous-specific.