Carbon-13 nuclear magnetic resonance study of nucleotide-metal interactions. Binding of manganese(II) with adenine nucleotides

A ternary acetylcholine—manganese—ATP complex

“…From the proton-manganese distances obtained in this study it is difficult to suggest a definite geometry for the ternary complex. Inspection of molecular models reveals that these distances are consistent with a model in which the manganese ion is associated with the a-and/~-phosphates and the N-7 nitrogen of ATP [10,11 ], the positively charged N-trimethyl group of acetylcholine with the 7-phosphate, the acetyl group being hydrogen-bonded either to the ribose hydroxyls or to the adenine NH2 group. It is emphasized that while such models make chemical sense they do not stem directly from the present results.…”

Investigation of the solution conformation of coenzyme A and its derivatives by hydrogen-1 and phosphorus-31 fast Fourier transform nuclear magnetic resonance spectroscopy

“…However, in adenosine, Mn(II) ions do not create any significant line broadening,34 even though in this instance, also, it could be weakly bound to N (7). 36 In addition, the chemical shift data for the C(2)-H and C( 8)-H in Table IA at pH 8.0 and pH 5.0 clearly show that the C( 8)-H chemical shift in 3',5'-ADP is highly sensitive to the ionization of the 5'-phosphate. Such an effect is best rationalized based on a preferential anti orientation.…”

Carbon-13 nuclear magnetic resonance studies of cyanocobalamin and several of its analogs

“…The identity of the four nonprotonated carbons (B-5, B-6, B-8, and B-9) was established by line-broadening experiments with the paramagnetic ion Mn2+. Kotowycz & Hayamizu (1973) have demonstrated that Mn2+ binds to N-7 of the adenine moiety of adenosine S'-phosphate (AMP), and thus the corresponding interaction with -ribazole should be at N-3. The addition of Mn2+ ions (2.5 X 10~5 M) to a neutral solution of a-ribazole 0 Chemical shifts downfield in parts per million with respect to external neat tetramethylsilane.…”