Biomimetic Modeling of Ni-ARD’s Active Site with Zinc and Nickel Metal Complexes
Abstract
The acireductone dioxygenase (ARD) metalloenzymes regulates the formation of the polyamine biosynthesis inhibitor methylthioadenosine through the methionine salvage pathway, a biosynthetic pathway in plants and prokaryotes. The ARD protein incorporates nickel or iron depending on bioavailability. The Fe-ARD and Ni-ARD demonstrate unique structure-function relationship dependent solely on the metal bound. Both metal congeners share identical amino acid residues yet when Fe2+is incorporated into the metal center the catalytic activity change causes an off-pathway shunt. Dr. Santiago Toledo of Texas Lutheran University developed a family of biomimetic models of the ARD metalloenzymes, [NiII(OMe2(6-H-DPPN))], [ZnII(OMe2(6-HDPPN))], [ZnII(OPh(6-H-DPPN))] and [ZnII(OPh(6-HDPEN))], that approximates nickel and zinc coordination at the active site. Density Functional (DFT) computational investigations have been performed and theoretical molecules been shown to be identical in geometry to the experimental data which help provide insight to the metal dependence of this system.
Session Name:
Chemistry I
Start Date
10-4-2015 9:00 AM
End Date
10-4-2015 10:00 AM
Location
HSB 209
Biomimetic Modeling of Ni-ARD’s Active Site with Zinc and Nickel Metal Complexes
HSB 209
The acireductone dioxygenase (ARD) metalloenzymes regulates the formation of the polyamine biosynthesis inhibitor methylthioadenosine through the methionine salvage pathway, a biosynthetic pathway in plants and prokaryotes. The ARD protein incorporates nickel or iron depending on bioavailability. The Fe-ARD and Ni-ARD demonstrate unique structure-function relationship dependent solely on the metal bound. Both metal congeners share identical amino acid residues yet when Fe2+is incorporated into the metal center the catalytic activity change causes an off-pathway shunt. Dr. Santiago Toledo of Texas Lutheran University developed a family of biomimetic models of the ARD metalloenzymes, [NiII(OMe2(6-H-DPPN))], [ZnII(OMe2(6-HDPPN))], [ZnII(OPh(6-H-DPPN))] and [ZnII(OPh(6-HDPEN))], that approximates nickel and zinc coordination at the active site. Density Functional (DFT) computational investigations have been performed and theoretical molecules been shown to be identical in geometry to the experimental data which help provide insight to the metal dependence of this system.