PMID- 4041439
OWN - NLM
STAT- MEDLINE
DCOM- 19851115
LR  - 20190613
IS  - 0006-2960 (Print)
IS  - 0006-2960 (Linking)
VI  - 24
IP  - 14
DP  - 1985 Jul 2
TI  - Effects of detergent on substrate binding and spin state of purified liver 
      microsomal cytochrome P-450LM2 from phenobarbital-treated rabbits.
PG  - 3809-14
AB  - Spectral changes accompanying the binding of the nonionic detergent n-octyl 
      beta-D-glucopyranoside (n-octyl glucoside) to cytochrome P-450LM2 purified from 
      liver microsomes of phenobarbital-treated rabbits have been compared to changes 
      in catalytic activity obtained in a reconstituted system consisting of various 
      levels of detergent, P-450LM2, and NADPH-cytochrome P-450 reductase. In the 
      absence of substrate and reductase, addition of n-octyl glucoside to 2-3 mM 
      resulted in a difference spectrum (detergent-bound minus detergent-free 
      cytochrome) characterized by a small maximum at 390 nm and a minimum at 410 nm, 
      suggestive of a slight stabilization of the high-spin (S = 5/2) state of the 
      cytochrome. As the detergent concentration was increased to 4-8 mM (corresponding 
      to maximal activity and pentameric or hexameric P-450), a new peak appeared at 
      427 nm while the minimum remained at 410 nm. Between 10 and 30 mM n-octyl 
      glucoside (conditions which produced catalytically inactive and monomeric P-450) 
      the minimum in the difference spectrum shifted to 390 nm and the maximum to 425 
      nm, characteristic of a shift in spin equilibrium toward low-spin (S = 1/2) 
      cytochrome. At low and high detergent concentrations, substrate [d-benzphetamine 
      with n-octyl glucoside or cyclohexane with the zwitterionic detergent 
      3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS)] was bound to 
      P-450LM2 with formation of high-spin P-450, although the increase in high-spin 
      cytochrome was less at high detergent levels than at low. The affinity of P-450 
      for substrate decreased by 2-3-fold at high detergent.(ABSTRACT TRUNCATED AT 250 
      WORDS)
FAU - Wagner, S L
AU  - Wagner SL
FAU - Gray, R D
AU  - Gray RD
LA  - eng
GR  - GM25738/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Biochemistry
JT  - Biochemistry
JID - 0370623
RN  - 0 (Detergents)
RN  - 0 (Glucosides)
RN  - 0 (Glycosides)
RN  - 0 (Surface-Active Agents)
RN  - 29836-26-8 (octyl-beta-D-glucoside)
RN  - 9035-51-2 (Cytochrome P-450 Enzyme System)
RN  - YQE403BP4D (Phenobarbital)
SB  - IM
MH  - Animals
MH  - Cytochrome P-450 Enzyme System/isolation & purification/*metabolism
MH  - Detergents/*pharmacology
MH  - Glucosides/*pharmacology
MH  - Glycosides/*pharmacology
MH  - Kinetics
MH  - Male
MH  - Microsomes, Liver/drug effects/*metabolism
MH  - Phenobarbital/*pharmacology
MH  - Protein Binding
MH  - Rabbits
MH  - Spectrophotometry
MH  - Surface-Active Agents/*pharmacology
EDAT- 1985/07/02 00:00
MHDA- 1985/07/02 00:01
CRDT- 1985/07/02 00:00
PHST- 1985/07/02 00:00 [pubmed]
PHST- 1985/07/02 00:01 [medline]
PHST- 1985/07/02 00:00 [entrez]
AID - 10.1021/bi00335a058 [doi]
PST - ppublish
SO  - Biochemistry. 1985 Jul 2;24(14):3809-14. doi: 10.1021/bi00335a058.