Polythymidylic acids

In either case, polyuridylic acid or polythymidylic acid, the rate of dimer formation will not be that calculated for an assemblage of independent sites, as in a solution of mononucleotide or dinucleotide, given by eq. (11). The sites are not independent but are in a connected sequence along a one-dimensional chain, and the rate of dimer formation will begin to deviate from the rate law of eq. (11) as soon as the location of unreacted sites becomes an important factor, certainly when... 

Formation of dimers in polythymidylic acid in 0.05M NaCl containing 50% ethylene glycol was followed by absorbance change143 at several temperatures. The quantum yield at 77°K was an order of magnitude greater than at 298°K. No evidence for hydrate formation was found. 

Fig. 1. The reduced adsorbed amount (0=Ns/Ns>max) as a function of time with 0.1 mg/ml of polythymidylic acid on cationic polystyrene latexes at 20°C and a 10 mmol/1 phosphate buffer of pH 5.2. c7Latex 1

MALDI analyses is profoundly influenced by base composition. Thus, polythymidylic acids are readily analysed, but polydeoxyguanylic acids are a distinct challenge and mixed-base oligomers represent an intermediate situation. As a consequence of the increased stability of the glycosidic bond in RNA, it is more readily analysed than DNA. 

Miyoshi, K., Miyake, T Hozumi, T., and Itakura, K. (1980) Solid-phase synthesis of polynucleotides II Synthesis of polythymidylic acids by the block coupling phosphotriester method Nucl Acids Res 8,5473-5489... 

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