Active species for Ce(IV)-induced hydrolysis of phosphodiester linkage in cAMP and DNA.
The hydrolysis of cyclic adenosine 3',5'-monophosphate and 2'-deoxythymidylyl(3'-5')2'-deoxythymidine by Ce(NH4)2(NO3)6 was kinetically studied. The rate of hydrolysis was fairly proportional to the concentration of [Ce2(IV) (OH)4]4+ , showing that this is the catalytically active species. According to quantum-chemical calculation, the two Ce(IV) ions in this [Ce2(IV) (OH)4]4+ cluster are bridged by two OH residues. Upon the complex formation with H2 PO4- (a model compound for the phosphodiesters), these two Ce(IV) ions bind the two oxygen atoms of the substrate and enhance the electrophilicity of the phosphorus atom. The catalytic mechanism of Ce(IV)-induced hydrolysis of phosphodiesters has been proposed on the basis these results.
Sumaoka
Jun
J
Research Center for Advanced Science and Technology, The University of Tokyo, Komaba, Tokyo, Japan.
Furuki
Kenichiro
K
Kojima
Yuki
Y
Shibata
Masahiko
M
Hirao
Kimihiko
K
Takeda
Naoya
N
Komiyama
Makoto
M
D002563:Cerium / Q000737:chemistry*; D000242:Cyclic AMP / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D004952:Esters / Q000737:chemistry*; D006868:Hydrolysis; D007700:Kinetics; D015394:Molecular Structure; D011465:Prostaglandins, Synthetic / Q000737:chemistry
D004952:Esters; D011465:Prostaglandins, Synthetic; D002563:Cerium; C026677:9 alpha,11 alpha,15 alpha-trihydroxy-16-phenoxy-17,18,19,20-tetranorprosta-4,5,13-trienoic acid; D004247:DNA; D000242:Cyclic AMP