Modelling heme d1. The spectral properties of copper(II) porphyrindiones.
The heme d1 macrocycle of Ps. aeruginosa dissimilatory nitrite reductase is an iron porphyrin-3,8-dione with a 17-acrylate substituent. We have compared the RR properties of Cu-d1, the copper(II) TME of extracted heme d1, with those of models that differ only with respect to the acrylate: Cu-17-acrylate mesoporphyrin-3,8-dione (2) and Cu-mesoporphyrin-3,8-dione (3). The RR spectrum of Cu-d1 is very similar to that of 2, including v(C = O) at approximately 1720 cm-1. Replacement of the acrylate with propionate changes the spectrum markedly. For example, the v(C = O) mode of 3 shifts to 1712 cm-1, and peaks of Cu-d1 and 2 at approximately 1400 and approximately 1535 cm-1 are shifted or absent from the spectrum of 3. FTIR spectra of 2 and 3 also differ in their voxo(C = O) frequencies. The acrylate thus has a surprisingly strong influence on the electronic structural and spectral properties of heme d1. These data provide a foundation for studies of the novel biological porphyrindione macrocycles.
Andersson
L A
LA
Department of Chemical and Biological Sciences, Oregon Graduate Institute, Beaverton 97006-1999.
Loehr
T M
TM
Wu
W S
WS
Chang
C K
CK
Timkovich
R
R
D000179:Acrylates / Q000032:analysis; D003300:Copper / Q000032:analysis*; D006418:Heme / Q000031:analogs & derivatives* / Q000032:analysis; D009247:NADH, NADPH Oxidoreductases / Q000032:analysis*; D009572:Nitrite Reductases / Q000032:analysis*; D011550:Pseudomonas aeruginosa / Q000201:enzymology*; D013055:Spectrophotometry, Infrared / Q000379:methods; D013059:Spectrum Analysis, Raman
D000179:Acrylates; D006418:Heme; C029400:heme d1; D003300:Copper; D009247:NADH, NADPH Oxidoreductases; D009572:Nitrite Reductases