Anomalous temperature dependence of the phosphorus-31 nuclear magnetic resonance chemical shift in d(CCGG) and d(CCTAGG) at the junction of the pyrimidine stack followed by the purine stack.
抄録
Two self-complementary deoxyribo-oligonucleotides, d(CCGG) and d(CCTAGG), were synthesized. Their 31P and ribose 1H nuclear magnetic resonance (NMR) assignments were achieved by the use of 31P-1H and 1H-1H shift correlated two-dimensional NMR techniques in low salt solution. One of the phosphorus atoms in each of these two origomers showed an anomalous behavior : its resonance was shifted to lower field instead of higher field on lowering the temperature in the range below the melting temperature. This "anomalous" 31P was assigned to CpG for d(CCGG), and TpA for d(CCTAGG). Among the four self-complementary G.C tetramers [d(CCGG), d(CGCG), d(GGCC), d(GCGC)], this anomalous behavior of 31P was found only in d(CCGG)[D.J.Patel, Biopolymers, 15, 533 (1976); ibid., 16, 1635 (1977); ibid., 18, 553 (1979)]. It was suggested from the results that a sequence 5'···(Py)p(Py)p(Pu)p(Pu)···3' always shows a conformational peculiarity at the (Py)p(Pu) portion, where Py=pyrimidine and Pu=purine nucleosides, and that the peculiarity involves the unusually low twist angle, tg, (i.e.the local residual rotation around the helix axis).The anomalous 31P behavior can be explained by postulating an intermediate form in the coil to helix transition.
収録刊行物
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- ＣＨＥＭＩＣＡＬ ＆ ＰＨＡＲＭＡＣＥＵＴＩＣＡＬ ＢＵＬＬＥＴＩＮ
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ＣＨＥＭＩＣＡＬ ＆ ＰＨＡＲＭＡＣＥＵＴＩＣＡＬ ＢＵＬＬＥＴＩＮ 34 (10), 3987-3993, 1986
公益社団法人 日本薬学会