PMID- 3015210
OWN - NLM
STAT- MEDLINE
DCOM- 19860925
LR  - 20190609
IS  - 0006-3002 (Print)
IS  - 0006-3002 (Linking)
VI  - 851
IP  - 1
DP  - 1986 Aug 13
TI  - Studies on the role of the oligomeric state and subunit III of cytochrome oxidase 
      in proton translocation.
PG  - 99-108
AB  - Anion-exchange fast protein liquid chromatography in the presence of 
      lauryldimethylamine N-oxide (LDAO) was introduced to separate cytochrome oxidase 
      into different complexes that either did or did not contain subunit III. Both 
      kinds of enzyme complex exhibited H+ translocation after reconstitution into 
      phospholipid vesicles, but with a significantly (approx. 50-60%) reduced H+/e- 
      ratio as compared with unchromatographed enzyme. The anion-exchange FPLC 
      fractions of the enzyme (with or without subunit III) sedimented more slowly than 
      the control enzyme upon sucrose gradient centrifugation in the presence of 
      cholate and a high potassium phosphate concentration. When the control enzyme was 
      subjected to the sucrose gradient centrifugation in the presence of LDAO or 
      Triton X-100, instead of cholate, one band containing all subunits was observed, 
      which sedimented slowly like the FPLC fractions. Transfer of this band to cholate 
      medium, and reapplication on the sucrose gradient (with cholate), yielded both a 
      slow- and a fast-migrating band after centrifugation. Enzyme complexes that 
      sedimented slowly or rapidly in the sucrose gradients revealed longer and shorter 
      elution times, respectively, in gel filtration FPLC. This suggests that these 
      complexes corresponds to monomers and dimers of cytochrome oxidase. 
      Solubilization of proteoliposomes and subsequent sucrose gradient centrifugation 
      in cholate yielded one fast-migrating band for the untreated enzyme, but both a 
      fast- and a slow-migrating band for the anion-exchange FPLC-treated enzyme, which 
      was exclusively slow-migrating before reconstitution into liposomes. It is 
      suggested that dimerisation of monomeric cytochrome oxidase may be favoured when 
      the enzyme encounters a membranous milieu, and that the dimeric structure might 
      be necessary for proton translocation.
FAU - Finel, M
AU  - Finel M
FAU - Wikstrom, M
AU  - Wikstrom M
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Netherlands
TA  - Biochim Biophys Acta
JT  - Biochimica et biophysica acta
JID - 0217513
RN  - 0 (Macromolecular Substances)
RN  - 0 (Protons)
RN  - EC 1.9.3.1 (Electron Transport Complex IV)
SB  - IM
MH  - Animals
MH  - Biological Transport
MH  - Cattle
MH  - Centrifugation, Density Gradient
MH  - Chromatography, High Pressure Liquid
MH  - Electron Transport Complex IV/*metabolism
MH  - Electrophoresis, Polyacrylamide Gel
MH  - Macromolecular Substances
MH  - Mitochondria, Heart/enzymology
MH  - *Protons
MH  - Structure-Activity Relationship
EDAT- 1986/08/13 00:00
MHDA- 1986/08/13 00:01
CRDT- 1986/08/13 00:00
PHST- 1986/08/13 00:00 [pubmed]
PHST- 1986/08/13 00:01 [medline]
PHST- 1986/08/13 00:00 [entrez]
AID - 0005-2728(86)90253-7 [pii]
AID - 10.1016/0005-2728(86)90253-7 [doi]
PST - ppublish
SO  - Biochim Biophys Acta. 1986 Aug 13;851(1):99-108. doi: 
      10.1016/0005-2728(86)90253-7.