PMID- 6833278
OWN - NLM
STAT- MEDLINE
DCOM- 19830527
LR  - 20210210
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 258
IP  - 8
DP  - 1983 Apr 25
TI  - Kinetic and structural investigation of acyl-binding sites on avian fatty acid 
      synthase.
PG  - 4802-7
AB  - The acyl-binding sites of avian fatty acid synthase have been further 
      characterized using the fluorescent acetyl-CoA analog, 
      beta-[N-(7-nitro-2,1,3-benzoxadiazol-4-yl]alanyl coenzyme A (NBDA-CoA). Binding 
      to nonsulfhydryl sites has been studied by treatment with neutralized 
      hydroxylamine to remove NBDA bound in a thioester linkage. The binding of NBDA to 
      hydroxylamine-insensitive sites can be divided into two types: "loose" and 
      "tight." The NBDA bound at the loose site can be removed by rapid gel filtration 
      through a centrifuge column or by added CoA and is kinetically competent to be 
      the loading site for acyl groups. The NBDA binds to the tight site apparently 
      irreversibly and inhibits the overall enzyme activity completely at a 
      stoichiometry of approximately 2 per enzyme molecule. Pyridoxal 5'-phosphate can 
      modify a large number of enzyme amino groups (greater than or equal to 20) and 
      totally inhibits the enoyl reductase activity. This inhibition appears to be 
      correlated with the binding of approximately four molecules of pyridoxal 
      5'-phosphate per enzyme molecule. Although the beta-ketoacyl reductase activity 
      is unimpaired, the binding of NADPH at the sites involved in this activity is 
      weakened. The fluorescence resonance energy transfer efficiency from NADPH, bound 
      to pyridoxal 5'-phosphate modified enzyme, to enzyme-bound NBDA, or from NADPH, 
      bound to unmodified enzyme, to NBDA bound only at the tight 
      hydroxylamine-insensitive sites is not significantly different from the overall 
      efficiency previously reported. This suggests that all of the acyl-binding sites 
      are located approximately the same distance from the enoyl reductase and 
      beta-ketoacyl reductase catalytic sites.
FAU - Cardon, J W
AU  - Cardon JW
FAU - Hammes, G G
AU  - Hammes GG
LA  - eng
GR  - GM 13292/GM/NIGMS NIH HHS/United States
GR  - GM 7806/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Fluorescent Dyes)
RN  - 0 (Oxadiazoles)
RN  - 5V5IOJ8338 (Pyridoxal Phosphate)
RN  - 86848-57-9 (beta-(N-(7-nitro-2,1,3-benzoxadiazol-4-yl))alanyl-coenzyme A)
RN  - EC 2.3.1.85 (Fatty Acid Synthases)
RN  - EQF2794IRE (4-Chloro-7-nitrobenzofurazan)
RN  - SAA04E81UX (Coenzyme A)
SB  - IM
MH  - *4-Chloro-7-nitrobenzofurazan/*analogs & derivatives
MH  - Animals
MH  - Binding Sites
MH  - Birds
MH  - Coenzyme A/*metabolism
MH  - Fatty Acid Synthases/*metabolism
MH  - Fluorescent Dyes/*metabolism
MH  - Kinetics
MH  - Oxadiazoles/*metabolism
MH  - Pyridoxal Phosphate/metabolism
MH  - Time Factors
EDAT- 1983/04/25 00:00
MHDA- 1983/04/25 00:01
CRDT- 1983/04/25 00:00
PHST- 1983/04/25 00:00 [pubmed]
PHST- 1983/04/25 00:01 [medline]
PHST- 1983/04/25 00:00 [entrez]
AID - S0021-9258(18)32496-7 [pii]
PST - ppublish
SO  - J Biol Chem. 1983 Apr 25;258(8):4802-7.