MAGNETIC-ORDERING IN SYNTHETIC OLIGONUCLEOTIDES - A DEUTERIUM NUCLEAR-MAGNETIC-RESONANCE INVESTIGATION

Deuterium NMR of the [methyl 2H]-2′-deoxythymidine labeled synthetic oligonucleotide, [d(CGCGAAT*T*CGCG)]2 in a liquid crystal phase are reported. This ordered phase was observed for hydrated samples with DNA concentrations ranging from 490 to 722 mg ml-1. Temperature variation of line shape and quadrupolar echo decay times were investigated, allowing the degree of alignment and changes in dynamics to be determined. At greatly reduced temperatures a cylindrical line shape was observed, as is expected for samples with the DNA helix axis aligned perpendicular to the magnetic field, while at ambient temperatures, motion about the helix axis averages this cylindrical line shape. NMR investigations at magnetic field strengths of 11.7, 9.4, and 4.7 T resulted in only minor variation in the degree of alignment. © 1990 American Institute of Physics.