Bibliography: p. 181-184.The aqueous solution conformation of SAH and SAM has been investigated using lanthanide probes. SAH at pH 7.0 interacts normally with lanthanide aquo ions and lanthanide-EDTA complexes via coordination at the carboxyl group. The conformation of the homocysteine fragment is found to, be extended but bent back towards the adenine base. SAM does not interact with lanthanide aquo ions in the pH region 2-7. It does form complexes with lanthanide-EDTA species via an ion-pairing mechanism rather than direct coordination. In addition to lanthanide probes, 250 MHz 1H n.m.r. spectra yielded vicinal JHH coupling constants from which the ribose conformation in both SAM and SAH could be more accurately determined
