Nucleoside complexing: A 13C NMR spectroscopic study of binding of metal ions to guanosine and related nucleosides in solution. Evidence for O-6 binding under basic conditions

• Type: Article in International Scientific Journal
• Date: 1982

Authors

Marzilli, LG (Author) Other; De Castro, B (Author) FCUP; Solorzano, C (Author) Other

Journal

Title: Journal of the American Chemical Society

Vol. 104

Pages: 461-466

ISSN: 0002-7863

Publisher: American Chemical Society

Indexing

ISI Web of Knowledge

Scopus - 41 Citations

Other information

Authenticus ID: P-007-2C5

Abstract (EN): The influence of hard and soft metals on the 13C NMR spectrum of guanosine and inosine under both neutral and basic conditions in Me2SO has been determined. Several related molecules also studied include 2¿-deoxyguanosine, 1-methylguanosine, and N2,N2-dimethylguanosine. Under neutral conditions, hard metal species such as Ba(NO3)2 and Pr(NO3)3 do not perturb the 13C NMR spectrum of guanosine, but under basic conditions (in the presence of the amine base triethylamine) a considerable change in the 13C NMR spectrum is observed. An analogous effect is observed for N2,N2-dimethylguanosine, but is absent for 1-methylguanosine. Under neutral conditions, soft metal species such as HgCl2 bind readily to guanosine, 1-methylguanosine, and N2,N2-dimethylguanosine, but in the presence of the amine base triethylamine, HgCl2 binds only to guanosine. Triethylamine alone does not significantly perturb the 13C NMR spectrum of guanosine or its derivatives, and these results suggest that metals do promote deprotonation at N(1). The shifts observed are best interpreted as resulting from the binding of the hard metal species to O(6) of guanosine when N(1) is deprotonated and the binding of the soft metal species to N(1) after deprotonation. The influence of metal ions on the 13C NMR shifts with 1-methylguanosine and N2,N2-dimethylguanosine is consistent with these binding site assignments. © 1982 American Chemical Society.

Language: English

Type (Professor's evaluation): Scientific