Anti-C5 monoclonal antibody, clone NN1719-7I24

RNAs especially the noncoding RNAs which lack protein-coding capacity but have critical functions in a wide range of cellular processes have received increased attention. They are reported to be associated with normal development and physiology, and their disruption would cause cancer. RNAs are dynamic molecules and the structural transition of them is fundamental to many RNA-involved cellular processes. The study of transition dynamics is critical to gaining knowledge on how the transition occurs, what factors govern the transition, and how to externally regulate the transition. Previously, we have reported the synthesis of sulfonated pyrene,SPy, and its application as a photoregulator for single-stranded DNA (ssDNA) looping. Herein, we studied the dynamics of single-stranded RNA (ssRNA) looping in aqueous solution by usingSPyas both a probe and a photoregulator. The rate of end-to-end loop formation in ssRNA regulated bySPyupon photostimulation suggests a retarding impact of the ribose 2 '-OH. The results also attest that (rU)(n)sequences are endowed with higher flexibility compared with (dT)(n)sequences and demonstrate the slowing down effect of C5-CH(3)group in thymine base on the looping dynamics of polythymine sequences. The photoregulated ssRNA looping observed herein occurs at mu s to tens of mu s time scales. All the findings provide important insight into the flexibility and structural transition dynamics of oligonucleotides.

A high-yielding method for the synthesis of 2H-1,3,5-oxadiazines by rhodium(II)- or copper(II)-catalyzed reaction of 1,2,4-oxadiazoles with alpha-diazo esters has been developed. The reaction proceeds via attack of the metallocarbenoid on the oxadiazole N2 atom followed by ring opening/1,6-electrocyclization and enables the introduction of alkyl, aryl, oxy, and amino substituents into the 6-position and electron-withdrawing groups into the 2-position of 1,3,5-oxadiazine. The N2-attack and the N4-attack of the carbenoid cause different oxadiazole ring openings, which are controlled by the substitution at C5. The presence of a substituent at this position is a prerequisite for the N2-attack to occur, leading to the formation of 1,3,5-oxadiazines.