BIOINORGANIC CHEMISTRY A Short Course Second Edition

448 IRON-CONTAINING PROTEINS AND ENZYMES

TABLE 7.10 Selected Bond Distances and Angles for Oxidized CcO Enzymes and

Fe

O

Cu

III

II

−−()

2 -- 2

or Fe

III

• (OH


• ) – Cu

II Model

Complexes CcO Crystal Structure or Model Compound

Bridging

Ligand

Fe · · · Cu

Distance (

Å )

Fe · · · X

a

Distance ( Å )

Cu · · · Y(X)

Distance (

Å )

Fe – X – Cu Angle ( ° )

PDB: 2OCC (bovine heart)

O

2 − 2

(possible)

4.85

2.28

2.02

119.6 (O2), 157.6 (O3)

R. sphaeroides

b (PDB: 1M56, 1M57)

OH

− or H

O 2

4.8

3.6

2.0

T. thermophilus

c (PDB: 1EHK)

O

2 −

, OH

− , or H

O 2

4.4

2.3

2.3

[(F

TPP)Fe 8

III

• (O

2 −

) – Cu

II (TMPA)]

+^

O

2 −

3.60

1.74

1.86

178

[(F

TPP)Fe 8

III

• (OH


• ) – Cu

II (TMPA)]

+d

OH

−^

3.66

1.87

1.89

157

[(

6 L)Fe

III

• O – Cu

II ]

+e

O

2 −

3.59

1.75

1.85

171

[(

5 L)Fe

III

• O – Cu

II ]

+d,e

O

2 −

3.40

1.77

1.84

141

a X equals the possible bridging ligands

O

2 − 2

, O

2 − , OH

− , or H

O. 2

b Reference 144. c Reference 157. d Bond distances and angles determined by X - ray absorption spectroscopy (XAS) methods

. See reference 138 and Figures 7.4

4 and 7.47.

e References 138 and 159.