TY - JOUR
T1 - Mössbauer study of the native, reduced and substrate‐reacted Desulfovibrio gigas aldehyde oxido‐reductase
AU - Barata, Belarmino A. S.
AU - Liang, Jin
AU - Moura, Isabel
AU - LeGall, Jean
AU - Moura, José J. G.
AU - Hanh Huynh, Boi
N1 - NIGMS NIH HHS (GM41482; GM 32187)
PY - 1992/1/1
Y1 - 1992/1/1
N2 - The Desulfovibrio gigas aldehyde oxido‐reductase contains molybdenum and iron‐sulfur clusters. Mössbauer spectroscopy was used to characterize the iron‐sulfur clusters. Spectra of the enzyme in its oxidized, partially reduced and benzaldehyde‐reacted states were recorded at different temperatures and applied magnetic fields. All the iron atoms in D. gigas aldehyde oxido‐reductase are organized as [2Fe‐2S] clusters. In the oxydized enzyme, the clusters are diamagnetic and exhibit a single quadrupole doublet with parameters (ΔEQ= 0.62 ± 0.02 mm/s and δ= 0.27 ± 0.01 mm/s) typical for the [2Fe‐2S]2+ state. Mössbauer spectra of the reduced clusters also show the characteristics of a [2Fe‐2S]1+ cluster and can be explained by a spin‐coupling model proposed for the [2Fe‐2S] cluster where a high‐spin ferrous ion (S= 2) is antiferromagnetically coupled to a high‐spin ferric ion (S= 5/2) to form a S= 1/2 system. Two ferrous sites with different ΔEQ values (3.42 mm/s and 2.93 mm/s at 85 K) are observed for the reduced enzyme, indicating the presence of two types of [2Fe‐2S] clusters in the D. gigas enzyme. Taking this observation together with the re‐evaluated value of iron content (3.5 ± 0.1 Fe/molecule), it is concluded that, similar to other Mo‐hydroxylases, the D. gigas aldehyde oxido‐reductase also contains two spectroscopically distinguishable [2Fe‐2S] clusters.
AB - The Desulfovibrio gigas aldehyde oxido‐reductase contains molybdenum and iron‐sulfur clusters. Mössbauer spectroscopy was used to characterize the iron‐sulfur clusters. Spectra of the enzyme in its oxidized, partially reduced and benzaldehyde‐reacted states were recorded at different temperatures and applied magnetic fields. All the iron atoms in D. gigas aldehyde oxido‐reductase are organized as [2Fe‐2S] clusters. In the oxydized enzyme, the clusters are diamagnetic and exhibit a single quadrupole doublet with parameters (ΔEQ= 0.62 ± 0.02 mm/s and δ= 0.27 ± 0.01 mm/s) typical for the [2Fe‐2S]2+ state. Mössbauer spectra of the reduced clusters also show the characteristics of a [2Fe‐2S]1+ cluster and can be explained by a spin‐coupling model proposed for the [2Fe‐2S] cluster where a high‐spin ferrous ion (S= 2) is antiferromagnetically coupled to a high‐spin ferric ion (S= 5/2) to form a S= 1/2 system. Two ferrous sites with different ΔEQ values (3.42 mm/s and 2.93 mm/s at 85 K) are observed for the reduced enzyme, indicating the presence of two types of [2Fe‐2S] clusters in the D. gigas enzyme. Taking this observation together with the re‐evaluated value of iron content (3.5 ± 0.1 Fe/molecule), it is concluded that, similar to other Mo‐hydroxylases, the D. gigas aldehyde oxido‐reductase also contains two spectroscopically distinguishable [2Fe‐2S] clusters.
UR - http://www.scopus.com/inward/record.url?scp=0026610349&partnerID=8YFLogxK
U2 - 10.1111/j.1432-1033.1992.tb16693.x
DO - 10.1111/j.1432-1033.1992.tb16693.x
M3 - Article
C2 - 1311679
AN - SCOPUS:0026610349
SN - 0014-2956
VL - 204
SP - 773
EP - 778
JO - European Journal of Biochemistry
JF - European Journal of Biochemistry
IS - 2
ER -