Poly- containing nucleic acid

Synthesis of Poly-L-Lysine Containing Nucleic Acid Bases... 

Water soluble poly(ethyleneimine) derivatives containing nucleic acid bases were prepared by the method described in previous papers (Scheme... 

Interaction of the synthetic polymers and polynucleotides were estimated from the hypochromicity values in UV spectra. The UV spectra were measured with a JASCO UV-660 spectrometer equipped with a temperature controller at 20 C. Polynucleotides were obtained from Yamasa Shoyu Co. Ltd. Water soluble poly(ethyleneimine) derivatives containing nucleic acid bases and polynucleotides were dissolved in Kolthoff buffer (pH 7.0, O.IM KH2PO4 -0.05M Na2B40 -10H20). These solutions were stocked for 2 days at 20 C, and then mixed to give a polymer mixture of 10 total concentration of nucleic acid base units in aqueous solution. 

Natural and synthetic polynucleotides are known to form polymer complexes by specific base-base interactions between nucleic acid bases. The synthetic nucleic acid analogs such as poly (methacryamide), poly-(ethyleneimine) and poly(L-lysine) derivatives containing nucleic acid bases were also found to form polymer complexes with polynucleotides by specific base-base interactions. Since the solubilities of these nucleic acid analogs in water were low, the specific interactions should be studied in organic solvents or water-organic mixed solvents, such as dimethyl sulfoxide, ethylene glucol, and water-propylene glycol. 

The contents of the nucleic acid bases in the poly-L-lysine derivatives were determined by UV spectra of the polymers after hydrolysis The polymers were hydrolyzed in 6 N-hydrochloric acid at 105°C for 24 hr, into lysine dihydrochloride and the carboxyethyl derivatives of the nucleic acid bases. The quantitative calculation was made relative to the standard sample of the carboxyethyl derivative of the nucleic acid bases. The analytical data are listed in Table 1. It was found that the thymine and uracil derivatives was completely substituted to polylysine. Low value in case of adenine base in the polymer may be attributed to the unstability of the activated ester, Ade-PNP (2), and may also be explained in terms of the steric interaction among bulky pendant groups of the polymer. When the poly-L-lysine containing about 50 mol % adenine units was again treated with Ade-PNP, the adenine unit content in the polymer increased up to 74 mol %(,] ). 

Poly(A)-agarose Nucleic acids containing poly(U) sequences, mRNA-binding proteins... 

Poly-L-lysine derivatives containing pendant nucleic acid bases were prepared by two different methods ... 

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