PMID- 9556556
OWN - NLM
STAT- MEDLINE
DCOM- 19980602
LR  - 20210209
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 273
IP  - 18
DP  - 1998 May 1
TI  - Mammalian thioredoxin reductase is irreversibly inhibited by dinitrohalobenzenes 
      by alkylation of both the redox active selenocysteine and its neighboring 
      cysteine residue.
PG  - 10835-42
AB  - The immunostimulatory dinitrohalobenzene compound 1-chloro-2, 4-dinitrobenzene 
      (DNCB) irreversibly inhibits mammalian thioredoxin reductase (TrxR) in the 
      presence of NADPH, inducing an NADPH oxidase activity in the modified enzyme 
      (Arner, E. S. J., Bjornstedt, M., and Holmgren, A. (1995) J. Biol. Chem. 270, 
      3479-3482). Here we have further analyzed the reactivity with the enzyme of DNCB 
      and analogues with varying immunomodulatory properties. We have also identified 
      the reactive residues in bovine thioredoxin reductase, recently discovered to be 
      a selenoprotein. We found that 4-vinylpyridine competed with DNCB for 
      inactivation of TrxR, with DNCB being about 10 times more efficient, and only 
      alkylation with DNCB but not with 4-vinylpyridine induced an NADPH oxidase 
      activity. A number of nonsensitizing DNCB analogues neither inactivated the 
      enzyme nor induced any NADPH oxidase activity. The NADPH oxidase activity of TrxR 
      induced by dinitrohalobenzenes generated superoxide, as detected by reaction with 
      epinephrine (the adrenochrome method). Addition of superoxide dismutase quenched 
      this reaction and also stimulated the NADPH oxidase activity. By peptide analysis 
      using mass spectrometry and Edman degradation, both the cysteine and the 
      selenocysteine in the conserved carboxyl-terminal sequence Gly-Cys-Sec-Gly (where 
      Sec indicates selenocysteine) were determined to be dinitrophenyl-alkylated upon 
      incubation of native TrxR with NADPH and DNCB. A model for the interaction 
      between TrxR and dinitrohalobenzenes is proposed, involving a functional FAD in 
      the alkylated TrxR generating an anion nitroradical in a dinitrophenyl group, 
      which in turn reacts with oxygen to generate superoxide. Production of reactive 
      oxygen species and inhibited reduction of thioredoxin by the modified thioredoxin 
      reductase after reaction with dinitrohalobenzenes may play a major role in the 
      inflammatory reactions provoked by these compounds.
FAU - Nordberg, J
AU  - Nordberg J
AD  - Medical Nobel Institute for Biochemistry I, Department of Medical Biochemistry 
      and Biophysics, Karolinska Institutet, S-171 77 Stockholm, Sweden.
FAU - Zhong, L
AU  - Zhong L
FAU - Holmgren, A
AU  - Holmgren A
FAU - Arner, E S
AU  - Arner ES
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Dinitrochlorobenzene)
RN  - 0 (Enzyme Inhibitors)
RN  - 0 (Pyridines)
RN  - 0CH9049VIS (Selenocysteine)
RN  - 11062-77-4 (Superoxides)
RN  - EC 1.8.1.9 (Thioredoxin-Disulfide Reductase)
RN  - I56G67XM8D (4-vinylpyridine)
RN  - K848JZ4886 (Cysteine)
SB  - IM
MH  - Alkylation
MH  - Amino Acid Sequence
MH  - Animals
MH  - Cattle
MH  - Chromatography, High Pressure Liquid
MH  - Cysteine/*chemistry
MH  - Dinitrochlorobenzene/*pharmacology
MH  - Enzyme Inhibitors/*pharmacology
MH  - Mass Spectrometry
MH  - Molecular Sequence Data
MH  - Oxidation-Reduction
MH  - Pyridines/pharmacology
MH  - Selenocysteine/*chemistry
MH  - Superoxides/metabolism
MH  - Thioredoxin-Disulfide Reductase/*antagonists & inhibitors/chemistry
EDAT- 1998/06/06 00:00
MHDA- 1998/06/06 00:01
CRDT- 1998/06/06 00:00
PHST- 1998/06/06 00:00 [pubmed]
PHST- 1998/06/06 00:01 [medline]
PHST- 1998/06/06 00:00 [entrez]
AID - S0021-9258(18)38279-6 [pii]
AID - 10.1074/jbc.273.18.10835 [doi]
PST - ppublish
SO  - J Biol Chem. 1998 May 1;273(18):10835-42. doi: 10.1074/jbc.273.18.10835.