Details
| Original language | English |
|---|---|
| Pages (from-to) | 3171-3177 |
| Number of pages | 7 |
| Journal | Biochemistry |
| Volume | 33 |
| Issue number | 11 |
| Publication status | Published - 1 Mar 1994 |
| Externally published | Yes |
Abstract
EPR and 1H, 14,15N ENDOR spectra are described for the type 1 and type 2 Cu(II) centers of dissimilatory nitrite reductase (NiR) from Alcaligenes xylosoxidans. The study was carried out on preparations of NiR containing both type 1 and type 2 Cu sites, and also on preparations of lower activity which contained essentially only type 1 Cu centers. This has enabled ENDOR studies of type 1 and type 2 sites to be carried out largely independently of each other, by appropriate choice of the excitation field. Spectra were recorded both in the absence and presence of nitrite, allowing a clear determination of which of the two types of Cu center constitutes the substrate binding site. The EPR results show large changes in the type 2 site gǁ (which decreases by 0.065) and CuAǁ (which increases by 2.0 mT) while the type 1 site EPR is not affected. In addition, both 1H and 14N ENDOR of the type 2 Cu site undergo considerable changes on addition of nitrite whereas the type 1 Cu site ENDOR is unaffected. Our results clearly demonstrate that nitrite binds to the type 2 copper and that this process significantly perturbs the ligation of this copper by the protein histidine residues. No 15N ENDOR resonances were observed from 15N nitrite. The accessibility of the copper sites to solvent has been studied using 2H2O. The results indicate that nitrite binds to the type 2 Cu by displacing a proton, probably on a water molecule bound to the copper atom.
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Biochemistry
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In: Biochemistry, Vol. 33, No. 11, 01.03.1994, p. 3171-3177.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - EPR and Electron Nuclear Double Resonance (ENDOR) Studies Show Nitrite Binding to the Type 2 Copper Centers of the Dissimilatory Nitrite Reductase of Alcaligenes xylosoxidans (NCIMB 11015)
AU - Howes, Barry D.
AU - Abraham, Zelda H.L.
AU - Lowe, David J.
AU - Brüser, Thomas
AU - Eady, Robert R.
AU - Smith, Barry E.
N1 - Copyright: Copyright 2017 Elsevier B.V., All rights reserved.
PY - 1994/3/1
Y1 - 1994/3/1
N2 - EPR and 1H, 14,15N ENDOR spectra are described for the type 1 and type 2 Cu(II) centers of dissimilatory nitrite reductase (NiR) from Alcaligenes xylosoxidans. The study was carried out on preparations of NiR containing both type 1 and type 2 Cu sites, and also on preparations of lower activity which contained essentially only type 1 Cu centers. This has enabled ENDOR studies of type 1 and type 2 sites to be carried out largely independently of each other, by appropriate choice of the excitation field. Spectra were recorded both in the absence and presence of nitrite, allowing a clear determination of which of the two types of Cu center constitutes the substrate binding site. The EPR results show large changes in the type 2 site gǁ (which decreases by 0.065) and CuAǁ (which increases by 2.0 mT) while the type 1 site EPR is not affected. In addition, both 1H and 14N ENDOR of the type 2 Cu site undergo considerable changes on addition of nitrite whereas the type 1 Cu site ENDOR is unaffected. Our results clearly demonstrate that nitrite binds to the type 2 copper and that this process significantly perturbs the ligation of this copper by the protein histidine residues. No 15N ENDOR resonances were observed from 15N nitrite. The accessibility of the copper sites to solvent has been studied using 2H2O. The results indicate that nitrite binds to the type 2 Cu by displacing a proton, probably on a water molecule bound to the copper atom.
AB - EPR and 1H, 14,15N ENDOR spectra are described for the type 1 and type 2 Cu(II) centers of dissimilatory nitrite reductase (NiR) from Alcaligenes xylosoxidans. The study was carried out on preparations of NiR containing both type 1 and type 2 Cu sites, and also on preparations of lower activity which contained essentially only type 1 Cu centers. This has enabled ENDOR studies of type 1 and type 2 sites to be carried out largely independently of each other, by appropriate choice of the excitation field. Spectra were recorded both in the absence and presence of nitrite, allowing a clear determination of which of the two types of Cu center constitutes the substrate binding site. The EPR results show large changes in the type 2 site gǁ (which decreases by 0.065) and CuAǁ (which increases by 2.0 mT) while the type 1 site EPR is not affected. In addition, both 1H and 14N ENDOR of the type 2 Cu site undergo considerable changes on addition of nitrite whereas the type 1 Cu site ENDOR is unaffected. Our results clearly demonstrate that nitrite binds to the type 2 copper and that this process significantly perturbs the ligation of this copper by the protein histidine residues. No 15N ENDOR resonances were observed from 15N nitrite. The accessibility of the copper sites to solvent has been studied using 2H2O. The results indicate that nitrite binds to the type 2 Cu by displacing a proton, probably on a water molecule bound to the copper atom.
UR - http://www.scopus.com/inward/record.url?scp=0028267847&partnerID=8YFLogxK
U2 - 10.1021/bi00177a005
DO - 10.1021/bi00177a005
M3 - Article
C2 - 8136351
AN - SCOPUS:0028267847
VL - 33
SP - 3171
EP - 3177
JO - Biochemistry
JF - Biochemistry
SN - 0006-2960
IS - 11
ER -