31P‐NMR studies of deoxyoligonucleotides

Publisher Website
Google Scholar
Abstract
The assignments of 31P resonances of eight short oligonucleotides have been achieved through specific heterodecoupling techniques reported previously from our laboratory [Cheng et al. (1982) Biopolymers 21, 697–701]. The temperature dependence of the assigned 31P chemical shifts of these oligomers was studied and compared to the constitutive dimeric units. This comparison gives some insight to the chemical‐shift values of the phosphorus resonances of oligonucleotides. (1) The 3′‐end terminal phosphorus resonance in an oligomer tends to locate at a spectral position relatively close to its constitutive dimeric unit. (2) On chain elongation (from 5′‐toward 3′‐end), the phosphorus resonance in the oligomer will be shifted upfield by 0.2–0.3 ppm, as compared to its constitutive dimeric unit. (3) The relative positions of phosphorus resonances in an oligomer tend to remain in the same order as their constitutive dimeric units. The above obsrvations lead to the development of a new procedure to assign the 31P resonance of a single‐stranded oligonucleotide.