A New Thiolate-Bound Dimanganese Cluster as a Structural and Functional Model for Class Ib Ribonucleotide Reductases |
| |
| Authors: | Beatrice Battistella Dr Thomas Lohmiller Dr Beatrice Cula Prof?Dr Peter Hildebrandt Dr Uwe Kuhlmann Prof?Dr Holger Dau Dr Stefan Mebs Prof?Dr Kallol Ray |
| |
| Institution: | 1. Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany;2. Institut für Chemie, Fakultät II, Technische Universität Berlin, Straße des 17.?Juni 135, 10623 Berlin, Germany;3. Institut für Physik, Freie Universität zu Berlin, Arnimallee 14, 14195 Berlin, Germany |
| |
| Abstract: | In class Ib ribonucleotide reductases (RNRs) a dimanganese(II) cluster activates superoxide (O2??) rather than dioxygen (O2), to access a high valent MnIII?O2?MnIV species, responsible for the oxidation of tyrosine to tyrosyl radical. In a biomimetic approach, we report the synthesis of a thiolate-bound dimanganese complex MnII2(BPMT)(OAc)2](ClO)4 (BPMT=(2,6-bis{bis(2-pyridylmethyl)amino]methyl}-4-methylthiophenolate) ( 1 ) and its reaction with O2?? to form a (BPMT)MnO2Mn]2+ complex 2 . Resonance Raman investigation revealed the presence of an O?O bond in 2 , while EPR analysis displayed a 16-line St=1/2 signal at g=2 typically associated with a MnIIIMnIV core, as detected in class Ib RNRs. Unlike all other previously reported Mn?O2?Mn complexes, generated by O2?? activation at Mn2 centers, 2 proved to be a capable electrophilic oxidant in aldehyde deformylation and phenol oxidation reactions, rendering it one of the best structural and functional models for class Ib RNRs. |
| |
| Keywords: | Bioinorganic Chemistry Dimanganese Cofactor Enzyme Models Phenol Oxidation Ribonucleotide Reductases |
|
|
