Measurement of the deuterium relaxation times in double-labeled (13C/2H) thymidine and 2′-deoxyadenosine and in the selectively labeled DNA duplex5′d(1C2G3A4T5T6A7A8T9C10G)23′

The and of deuterium in 13C/2H double-labeled 2@(R/S),5@(R/S)- T 1 T 1o 2H 2 -1@,2@,3@,4@,5@- 13C 5 -2@- and the corresponding thymidine derivative as well as in the non-uniformly labeled (shown in bold deoxyadenosine and underlined) DNA duplex, have been determined for the —rst time. These d5{(1C2G3A4T5T6A7A8T9C10G) 2, double-labelled nucleoside blocks have a special feature in that the geminal 2@¨2A and 5@¨5A protonproton coup- lings are eliminated by replacement with diastereomeric deuterium at C-2@ and C-5@ centers. This uniquely enables us to perform deuterium relaxation measurement experiments through selective polarization transfer, 1H¨13C¨2H¨ 13C¨1H at C-2@ and C-5@ centers, thereby allowing —ltration of all other naturally abundant methylene- and methine-13C as well as enriched methine-13C fragments. Comparison of and of 2H in double-labeled (13C/ T 1 T 1o 2H) 2@-deoxyadenosine and thymidine with that of the non-uniformly labeled DNA duplex, shows that the dynamics of various nucleotide residues are indeed non-uniform. d5{(1C2G3A4T5T6A7A8T9C10G) 2, Copyright 1999 John Wiley & Sons, Ltd. (