PMID- 11914083
OWN - NLM
STAT- MEDLINE
DCOM- 20020506
LR  - 20190613
IS  - 0006-2960 (Print)
IS  - 0006-2960 (Linking)
VI  - 41
IP  - 13
DP  - 2002 Apr 2
TI  - Cholate-induced dimerization of detergent- or phospholipid-solubilized bovine 
      cytochrome C oxidase.
PG  - 4371-6
AB  - Bovine heart cytochrome c oxidase (CcO), solubilized by either nonionic 
      detergents or phospholipids, completely dimerizes upon the addition of bile 
      salts, e.g., sodium cholate, sodium deoxycholate, or CHAPS. Bile salt induced 
      dimerization occurs whether dodecyl maltoside, decyl maltoside, or Triton X-100 
      is the primary solubilizing detergent or the enzyme is dispersed in 
      phosphatidylcholine, phosphatidylethanolamine, or mixtures thereof. In each case, 
      complete CcO dimerization can be verified by sedimentation velocity and 
      sedimentation equilibrium after correction for bound detergent and/or 
      phospholipid. The relative concentration of the bile salt is critical for 
      production of homogeneous, dimeric CcO. For example, enzyme solubilized by 2 mM 
      detergent requires an equal molar concentration of sodium cholate. Similarly, 
      enzyme dispersed in 20 mM phospholipid requires 50 mM sodium cholate, 
      concentrations that are commonly used to reconstitute CcO into small unilamellar 
      vesicles. Bile salts do more than just stabilize dimeric CcO and prevent 
      detergent-induced dissociation into monomers. They are able to completely reverse 
      detergent-induced monomerization and cause completely monomeric CcO to 
      reassociate. Dimeric CcO so generated is no more stable than the original complex 
      and easily dissociates into monomers if the bile salt is removed. The 
      dimerization process is dependent upon a full complement of subunits; e.g., if 
      subunits VIa and VIb are removed, the resulting monomeric CcO will not 
      reassociate upon the addition of sodium cholate. These results support four 
      important consequences: (1) dissociation of dimeric CcO into monomers is 
      reversible; (2) stable dimers can be produced under solution conditions; (3) 
      dimers can be stabilized even at relatively high pH and low enzyme concentration; 
      and (4) subunits VIa and VIb are required for dimerization.
FAU - Musatov, Andrej
AU  - Musatov A
AD  - Department of Biochemistry, The University of Texas Health Science Center, 7703 
      Floyd Curl Drive, San Antonio, Texas 78229-3900, USA.
FAU - Robinson, Neal C
AU  - Robinson NC
LA  - eng
GR  - GMS 24795/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Biochemistry
JT  - Biochemistry
JID - 0370623
RN  - 0 (Bile Acids and Salts)
RN  - 0 (Cholates)
RN  - 0 (Cholic Acids)
RN  - 0 (Detergents)
RN  - 0 (Micelles)
RN  - 0 (Phospholipids)
RN  - 005990WHZZ (Deoxycholic Acid)
RN  - EC 1.9.3.1 (Electron Transport Complex IV)
RN  - QBP25342AG (3-((3-cholamidopropyl)dimethylammonium)-1-propanesulfonate)
SB  - IM
MH  - Animals
MH  - Bile Acids and Salts/pharmacology
MH  - Cattle
MH  - Cholates/*pharmacology
MH  - Cholic Acids/pharmacology
MH  - Chromatography, Ion Exchange
MH  - Deoxycholic Acid/pharmacology
MH  - Detergents/*pharmacology
MH  - Dimerization
MH  - Dose-Response Relationship, Drug
MH  - Electron Transport Complex IV/chemistry/*metabolism
MH  - Hydrogen-Ion Concentration
MH  - Micelles
MH  - Myocardium/chemistry
MH  - Phospholipids/*pharmacology
MH  - Protein Binding
MH  - Protein Structure, Tertiary
EDAT- 2002/03/27 10:00
MHDA- 2002/05/07 10:01
CRDT- 2002/03/27 10:00
PHST- 2002/03/27 10:00 [pubmed]
PHST- 2002/05/07 10:01 [medline]
PHST- 2002/03/27 10:00 [entrez]
AID - bi016080g [pii]
AID - 10.1021/bi016080g [doi]
PST - ppublish
SO  - Biochemistry. 2002 Apr 2;41(13):4371-6. doi: 10.1021/bi016080g.