Cadmium II Complexes of Nucleotide Analogues

The use of structurally altered nucleotides as probes is one way to study reactions of enzymes which involve nucleotides as substrates. Another goal for structural alterations is the hope to obtain compounds with useful pharmaceutical properties. In fact, over the years aU three parts of nucleotides have been systematically 

Formation of a l,N -etheno bridge at the adenine residue leads to a 1,10-phenanthroline-like metal ion binding site in adenosine and gives so-called -adenosine (e-Ado) [171]. It is thus no surprise that the stability of the Cd complexes increases by a factor of more than 10 by going from adenosine (log S(Ado) = Table 3) to e-adenosine (log d(s-Ado) = [175]). It may 

In Section 6.3 we have seen that Cd(ATP) experiences a stability enhancement of log dcd/ATP = 0.27 0.04 (Table 11) due to N7 binding of the phosphate-coordinated Cd and that the macrochelate reaches a formation degree of about 45% (Table 11). There is no value known for Cd(e-ATP), but the extra stability enhancement for Zn(e-ATP) by going from Zn(ATP) Gog Izh/atp = 0.27 Table 11) to Zn(e-ATP) Gog dzn/s-AXP = 0-62 [179]) amounts to about 0.35 log unit hence, one estimates for Cd(e-ATP) a stability enhancement of about 0.6 (= log dcd/e-ATp) meaning that the formation degree of Cd(e-ATP) j amounts 

To conclude, it is evident that great care needs to be exercised if s-adenosine phosphates are employed as probes for adenosine phosphates in the presence of Cd or other divalent 3d-transition metal ions. 

The phosphate group of nucleotides has been altered in many ways [170]. The most popular alteration probably is the substitution of one of the oxygens by a sulfur atom. Such derivatives are then commonly employed as probes in libozymes 

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