PMID- 18217775
OWN - NLM
STAT- MEDLINE
DCOM- 20080508
LR  - 20080213
IS  - 0006-2960 (Print)
IS  - 0006-2960 (Linking)
VI  - 47
IP  - 7
DP  - 2008 Feb 19
TI  - Redox-linked structural changes associated with the formation of a catalytically 
      competent form of the diheme cytochrome c peroxidase from Pseudomonas aeruginosa.
PG  - 1947-56
LID - 10.1021/bi702064f [doi]
AB  - A recombinant form of the prototypic diheme bacterial cytochrome c peroxidase 
      (BCCP) from Pseudomonas aeruginosa (PsaCCP) has been expressed in Escherichia 
      coli and purified to homogeneity. This material was used to carry out the first 
      integrated biochemical, spectroscopic and structural investigation of the factors 
      leading to reductive activation of this class of enzymes. A single, tightly 
      bound, Ca2+ ion (K = 3 x 10(10) M-1) found at the domain interface of both the 
      fully oxidized and mixed-valence forms of the enzyme is absolutely required for 
      catalytic activity. Reduction of the electron-transferring (high-potential) heme 
      in the presence of Ca2+ ions triggers substantial structural rearrangements 
      around the active-site (low-potential) heme to allow substrate binding and 
      catalysis. The enzyme also forms a mixed-valence state in the absence of Ca2+ 
      ions, but a combination of electronic absorption, and EPR spectroscopies suggests 
      that under these circumstances the low potential heme remains six-coordinate, 
      unable to bind substrate and therefore catalytically inactive. Our observations 
      strongly suggest that the two mixed-valence forms of native PsaCCP reported 
      previously by Foote and colleagues (Foote, N., Peterson, J., Gadsby, P., 
      Greenwood, C., and Thomson, A. (1985) Biochem. J. 230, 227-237) correspond to the 
      Ca2+-loaded and -depleted forms of the enzyme.
FAU - Echalier, Aude
AU  - Echalier A
AD  - Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, 
      United Kingdom.
FAU - Brittain, Thomas
AU  - Brittain T
FAU - Wright, Joshua
AU  - Wright J
FAU - Boycheva, Svetlana
AU  - Boycheva S
FAU - Mortuza, Gulnahar B
AU  - Mortuza GB
FAU - Fulop, Vilmos
AU  - Fulop V
FAU - Watmough, Nicholas J
AU  - Watmough NJ
LA  - eng
SI  - PDB/2VHD
GR  - 066363/Z/01/Z/Wellcome Trust/United Kingdom
GR  - B10987/Biotechnology and Biological Sciences Research Council/United Kingdom
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20080125
PL  - United States
TA  - Biochemistry
JT  - Biochemistry
JID - 0370623
RN  - 0 (DNA Primers)
RN  - EC 1.11.1.5 (Cytochrome-c Peroxidase)
SB  - IM
MH  - Base Sequence
MH  - Catalysis
MH  - Cytochrome-c Peroxidase/*chemistry/metabolism
MH  - DNA Primers
MH  - Mass Spectrometry
MH  - Oxidation-Reduction
MH  - Protein Conformation
MH  - Pseudomonas aeruginosa/*enzymology
MH  - Spectrophotometry, Ultraviolet
EDAT- 2008/01/26 09:00
MHDA- 2008/05/09 09:00
CRDT- 2008/01/26 09:00
PHST- 2008/01/26 09:00 [pubmed]
PHST- 2008/05/09 09:00 [medline]
PHST- 2008/01/26 09:00 [entrez]
AID - 10.1021/bi702064f [doi]
PST - ppublish
SO  - Biochemistry. 2008 Feb 19;47(7):1947-56. doi: 10.1021/bi702064f. Epub 2008 Jan 
      25.