Open AccessDetermination of the syn‐anti Equilibrium of Some Purine 3′:5′‐Nucleotides by Nuclear‐Magnetic‐Relaxation Perturbation in the Presence of a Lanthanide‐Ion Probe
Author(s) -
FAZAKERLEY G. Victor,
RUSSELL Jill C.,
WOLFE Melanie A.
Publication year - 1977
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1977.tb11630.x
Subject(s) - chemistry , nucleotide , steric effects , aqueous solution , substituent , purine , lanthanide , dynamic equilibrium , stereochemistry , crystallography , ribose , ion , organic chemistry , biochemistry , gene , enzyme
The aqueous solution conformation of four purine 3′:5′‐nucleotides varying in their substituents at C‐6 and C‐8 has been studied using gadolinium(III) to perturb the proton relaxation times. The ribose conformations are inferred. All the nucleotides are best described as being in a dynamic equilibrium between syn and anti conformations and the position of this equilibrium is not dramatically affected by changing the substituent at C‐6. These nucleotides in their neutral base form slightly favour an anti conformation. In the presence of a bulky methylthio group at C‐8 the equilibrium is shifted towards a dominance from the syn conformation due to steric repulsion factors.