Loading…
Effect of the ribose versus 2'-deoxyribose residue on the metal ion-binding properties of purine nucleotides
The interaction between metal ions and nucleotides is well characterized, as is their importance for metabolic processes, e.g. in the synthesis of nucleic acids. Hence, it is surprising to find that no detailed comparison is available of the metal ion-binding properties between nucleoside 5'-ph...
Saved in:
Published in: | Dalton transactions : an international journal of inorganic chemistry 2008-10 (39), p.5368-5377 |
---|---|
Main Authors: | , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Summary: | The interaction between metal ions and nucleotides is well characterized, as is their importance for metabolic processes, e.g. in the synthesis of nucleic acids. Hence, it is surprising to find that no detailed comparison is available of the metal ion-binding properties between nucleoside 5'-phosphates and 2'-deoxynucleoside 5'-phosphates. Therefore, we have measured here by potentiometric pH titrations the stabilities of several metal ion complexes formed with 2'-deoxyadenosine 5'-monophosphate (dAMP2-), 2'-deoxyadenosine 5'-diphosphate (dADP3-) and 2'-deoxyadenosine 5'-triphosphate (dATP4-). These results are compared with previous data measured under the same conditions and available in the literature for the adenosine 5'-phosphates, AMP(2-), ADP(3-) and ATP(4-), as well as guanosine 5'-monophosphate (GMP(2-)) and 2'-deoxyguanosine 5'-monophosphate (dGMP(2-)). Hence, in total four nucleotide pairs, GMP(2-)/dGMP(2-), AMP(2-)/dAMP(2-), ADP(3-)/dADP(3-) and ATP(4-)/dATP(4-) (= NP/dNP), could be compared for the four metal ions Mg2+, Ni2+, Cu2+ and Zn2+ (= M2+). The comparisons show that complex stability and extent of macrochelate formation between the phosphate-coordinated metal ion and N7 of the purine residue is very similar (or even identical) for the AMP(2-)/dAMP(2-) and ADP(3-)/dADP(3-) pairs. In the case of the complexes formed with ATP(4-)/dATP(4-) the 2'-deoxy complexes are somewhat more stable and show also a slightly enhanced tendency for macrochelate formation. This is different for guanine nucleotides: the stabilities of the M(dGMP) complexes are clearly higher, as are the formation degrees of their macrochelates, than is the case with the M(GMP) complexes. This enhanced complex stability and greater tendency to form macrochelates can be attributed to the enhanced basicity (DeltapKaca. 0.2) of N7 in the 2'-deoxy compound. These results allow general conclusions regarding nucleic acids to be made. |
---|---|
ISSN: | 1477-9226 1477-9234 |
DOI: | 10.1039/b805911j |