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Modelling heme d 1
Author(s) -
Andersson Laura A.,
Loehr Thomas M.,
Wu Weishih,
Chang Chi K.,
Timkovich Russell
Publication year - 1990
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(90)80946-g
Subject(s) - heme , chemistry , biochemistry , enzyme
The heme d 1 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‐ d 1 , the copper(II) TME of extracted heme d 1 , 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‐ d 1 is very similar to that of 2, including v (C=O) at ~ 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‐ d 1 and 2 at ~ 1400 and ~ 1535 cm −1 are shifted or absent from the spectrum of 3. FTIR spectra of 2 and 3 also differ in their ν oxo (C=O) frequencies. The acrylate thus has a surprisingly strong influence on the electronic structural and spectral properties of heme d 1 . These data provide a foundation for studies of the novel biological porphyrindione macrocycles.