Thymidine recognition

The regions of the tRNA molecule teferred to in Chapter 35 (and illustrated in Figure 35-11) now become important. The thymidine-pseudouridine-cyti-dine (T PC) arm is involved in binding of the amino-acyl-tRNA to the ribosomal surface at the site of protein synthesis. The D arm is one of the sites important for the proper recognition of a given tRNA species by its proper aminoacyl-tRNA synthetase. The acceptor arm, located at the 3 -hydroxyl adenosyl terminal, is the site of attachment of the specific amino acid. 

Eiichi Kimura is retired from the Department of Medicinal Chemistry at Hiroshima University in Japan. His recent research interests have included the supramolecular chemistry of macrocyclic polyamines and their use in molecular recognition and as zinc-enzyme models. These interests have led to the development of fluorophore sensors for Zn(II) [8] use of macrocycles to effect selective recognition of anions [9], nucleobases in polynucleotides [10], thymidine mono- and diphosphate nucleotides (11), carbonic anhydrase and carboxypeptidase [12], and development of Zn(II)-macrocycle anti-HIV agents [13], In May 2004, he received a Purple Ribbon Award from the Emperor of Japan. 

Aoki, S. and Kimura, E. (2000) Highly selective recognition of thymidine mono- and diphosphate nucleotides in aqueous solution by ditopic receptors zinc(II)-bis(cyclen) complexes (cyclen = 1, 4, 7, 10-tetraazacyclododecane), J. Am. Chem. Soc. 122, 4542-4548. 

To rule out specific recognition by the ethylguanine ligand as the mechanism of thymidine specificity, the complex Ru(bpy)2(dmap)OH22+ was prepared (dmap = 4-dimethylaminopyridine). The spectral and... 

THREE-POINT RECOGNITION OF THYMIDINE BY A ZINC(II)-CYCLEN COMPLEX ... 

Recognition of phosphate monoester dianions by 1 (ZnL ) + through 0 Zn +coordination results in the formation of a 1 1 complex 2 (Scheme 3.3), the dissociation constants (K ) of which are in the miUimolar order in aqueous solution at pH 7.4 (K = 0.8 mM when R = 4-nitrophenyl). It was also found that 1 recognizes imide-containing compounds such as thymidine (T) and forms a 1 1 complex 3, whose values are also in the millimolar order (K = 0.3 mM for 1-(T ) complex at pH 8). ... 

Kumar et reported the synthesis of pyrene-modified nucleotides and their effects in secondary nucleic acid structures. Pyrene was attached to the 5 -position of thymidine (26a) or to the 2 -position of 2 -deojgairidine via a triazolomethylene linker (26b), or via a triazole linker (26c). These nucleosides were converted into their phosphoramidites and then incorporated into oligonucleotides, and analysed by thermal stability and fluorescence studies. These experiments indicated that these oligonucleotides can act as specific recognition probes. 

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