Abstract:
:The reaction mechanism of a 1,4-benzoquinone reductase from the wood-rotting basidiomycete Phanerochaete chrysosporium was investigated. The native, oxidized, FMN-containing enzyme was reduced quantitatively by NADH and the resulting reduced enzyme was reoxidized in the presence of one equivalent of 2,6-di-methoxy-1,4-benzoquinone (DMBQ). The stoichiometry of NADH oxidation versus DMBQ reduction is 1:1. The enzyme catalyzes the reduction of quinones to hydroquinones by a ping-pong steady-state mechanism. However, inhibition is observed at low NADH concentrations. Quinone products derived from the autooxidation of the unstable compounds 1,2,4-trihydroxybenzene and 5-chloro-2,3,4-trihydroxybenzene also appear to be substrates for the quinone reductase. The enzyme reduces the one-electron acceptors ferricyanide and ferricytochrome c (Cc3+) with rates of 58.4 and 0.08%, respectively, compared to DMBQ. The stoichiometry of NADH oxidation versus ferricyanide reduction is 1:2. In the presence of quinones the rates of Cc3+ and ferricyanide reduction are increased, owing to the nonenzymatic reduction of these acceptors by enzyme-generated hydroquinone products. Dicumarol and Cibacron blue are competitive inhibitors with respect to NADH, with Ki values of 2.1 and 0.30 microM, respectively. Reconstitution of the apoprotein with FMN yields a fully active enzyme at an FMN-to-protein ratio of 2:1, suggesting that the flavin content of the enzyme is two molecules of FMN per dimer.
journal_name
Arch Biochem Biophysjournal_title
Archives of biochemistry and biophysicsauthors
Brock BJ,Gold MHdoi
10.1006/abbi.1996.0279subject
Has Abstractpub_date
1996-07-01 00:00:00pages
31-40issue
1eissn
0003-9861issn
1096-0384pii
S0003986196902799journal_volume
331pub_type
杂志文章abstract::Heavy-atom isotope effects for the N-demethylation of nicotine have been determined in vivo in static-phase biosynthetically incompetent plant cell cultures of Nicotiana species. A (2)H kinetic isotope effect of 0.587 and a (15)N kinetic isotope effect of 1.0028 were obtained. An identical (15)N kinetic isotope effect...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/j.abb.2006.12.013
更新日期:2007-02-15 00:00:00
abstract::Rats fed an ethanol-containing diet for 4 weeks showed a 3- to 5-fold increase over isocalorically pair-fed controls with respect to cytosolic NAD(P)H-quinone oxidoreductase (NQOR) (E.C.1.6.99.2) with both menadione and dichlorophenol-indophenol as substrates. Rates of NAD(P)H-dependent p-nitrosophenol (pNSP) reductio...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(92)90510-4
更新日期:1992-06-01 00:00:00
abstract::Previous studies in which dicyclohexylcarbodiimide (DCCD) was used to inactivate F1-ATPase enzymes have suggested that two glutamate residues in the beta-subunit are essential for catalysis. In the Escherichia coli F1-ATPase, these are residues beta-Glu-181 and beta-Glu-192. Oligonucleotide-directed mutagenesis was us...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(88)90121-x
更新日期:1988-02-15 00:00:00
abstract::Saccharomyces cerevisiae phosphoenolpyruvate carboxykinase [ATP:oxaloacetate carboxy-lyase (transphosphorylating), EC 4.1.1.49] is completely inactivated by the 2',3'-dialdehyde derivative of ATP (oATP) in the presence of Mn2+. The dependence of the pseudo-first-order rate constant on reagent concentration indicates t...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(88)90005-7
更新日期:1988-11-15 00:00:00
abstract::Diphtheria toxin (DT) induces the leakage of dipalmitoylphosphatidic acid (DPPA) membranes but not neutral dipalmitoylphosphatidylcholine (DPPC) membranes. Cholesterol incorporated into liposomes enhances the membrane leakage induced by DT in acidic DPPA membranes but not in neutral DPPC membranes. Membrane leakage wa...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(84)90317-5
更新日期:1984-10-01 00:00:00
abstract::The polymerization of alpha1-antitrypsin within the hepatic cell leads to alpha1-antitrypsin deficiency. Both the conformational changes and the kinetics of the polymerization process are poorly understood. Here we describe fluorescence experiments investigating the polymerization reaction using the fluorescent probe4...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.1998.0751
更新日期:1998-08-15 00:00:00
abstract::The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates the toxicity of dioxin and other xenobiotics. In the absence of exogenous ligand, AhR is cytosolic. We investigated how AhR is retained in the cytosol and how dioxin induces AhR to move to the nucleus. Disruption of nuclear ex...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.2001.2339
更新日期:2001-05-15 00:00:00
abstract::Diglycyl triperoxodivanadate [V2O2(O2)3(Gly H)2(H2O)2], a synthetic compound with mu-peroxo-bridge derived from H2O2 and vanadate, oxidized bromide to a bromination-competent intermediate in phosphate buffer and physiological pH. This is in contrast to the requirement of acid medium with H2O2 as the oxidant. Addition ...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.1997.0103
更新日期:1997-06-15 00:00:00
abstract::According to differences in mobility on SDS-polyacrylamide gel electrophoresis, calpastatins (inhibitor proteins of the calcium-dependent proteinase calpain) are classified into the tissue type (100-120 kDa) and the erythrocyte type (70 kDa), which lacks the amino-terminal domains (domains L and 1). We investigated th...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.1993.1294
更新日期:1993-06-01 00:00:00
abstract::Over the past three decades the protein folding field has undergone monumental changes. Originally a purely academic question, how a protein folds has now become vital in understanding diseases and our abilities to rationally manipulate cellular life by engineering protein folding pathways. We review and contrast past...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/j.abb.2007.05.014
更新日期:2008-01-01 00:00:00
abstract::Alcohol oxidase (AO) is a peroxisomal, homo-octameric flavoenzyme, which catalyzes methanol oxidation in methylotrophic yeast. Here, we report on the generation of soluble, FAD-lacking AO monomers. Using steady-state fluorescence, fluorescence correlation spectroscopy, circular dichroism and static light scattering ap...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/j.abb.2007.01.005
更新日期:2007-03-15 00:00:00
abstract::The influence of oxidative stress on agonist-stimulated changes of intracellular free calcium and inositol trisphosphate in the neurosecretory PC12 cell line was investigated. The oxidant H2O2 modulated the bradykinin-induced calcium signal by decreasing the initial peak and the plateau phase in the same manner as tet...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.1993.1527
更新日期:1993-11-01 00:00:00
abstract::The catalytic activity of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) decreased (almost linearly) as a function of increasing concentrations of tubulin; the total loss in activity was attained at a ratio of 1.2 to 1.8 tubulin dimer to GAPDH tetramer. Based on the inhibition data, a dissociation constant for the t...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.1994.1385
更新日期:1994-09-01 00:00:00
abstract::2-Isopropenyl-2-methyladamantane (2-PMADA) and 3-isopropenyl-3-methyldiamantane (3-PMDIA) showed potent and selective inhibition of cytochrome P450 (CYP) 2B6-mediated reactions with K(i) values of 5.27 and 2.17 microM, respectively. No effect on activities of other human CYP was found even at concentrations 100-fold h...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/S0003-9861(02)00259-X
更新日期:2002-07-01 00:00:00
abstract::The regulation of expression of hepatic iron-related proteins was examined during iron deficiency caused by scurvy in guinea pigs. Previous studies showed that some effects of scurvy, such as suppression of collagen gene expression, result from events associated with weight loss. During the initial phase of scurvy whe...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.1996.0037
更新日期:1996-01-15 00:00:00
abstract::It is established that high concentrations of nitric oxide(1) (NO), as released from activated macrophages, induce apoptosis in breast cancer cells. In this study, we assessed the potential of a light-activated NO donor [(Me2bpb)Ru(NO)(Resf)], a recently reported apoptototic agent, in suppressing the anchorage indepen...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/j.abb.2013.10.006
更新日期:2013-12-01 00:00:00
abstract::Bcl-2 family proteins regulate apoptosis through their homo- and heterodimerization. By protein sequence analysis and structural comparison, we have identified a conserved hydrophobic core at the BH1 and BH2 domains of Bcl-2 family proteins. The hydrophobic core is stabilized by hydrophobic interactions among the resi...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/j.abb.2009.01.003
更新日期:2009-04-01 00:00:00
abstract::Eleven hybridoma clones which secrete monoclonal antibodies against purified rat liver alcohol dehydrogenase (EC 1.1.1.1) were isolated. Antibodies (R-1-R-11) were identified by their ability to bind to immobilized pure alcohol dehydrogenase in an enzyme-linked immunoadsorbent assay, in which antibody R-9 showed the h...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(84)90233-9
更新日期:1984-12-01 00:00:00
abstract::The effects of extracellular ATP on phosphoinositide metabolism and intracellular Ca2+ homeostasis were studied in Ehrlich ascites tumor cells. Cytosolic [Ca2+] was measured using either quin 2 or the recently described indicator fura 2. Addition of 0.5-25 microM extracellular ATP to intact cells results in a rapid mo...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(86)90192-x
更新日期:1986-02-15 00:00:00
abstract::Under physiological conditions the uptake of transferrin-bound iron by reticulocytes involves transferrin binding to membrane receptors followed by endocytosis, release of iron from the transferrin within endosomes, and recycling of apotransferrin to the cell surface. However, as shown in the present work, iron uptake...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.1994.1045
更新日期:1994-01-01 00:00:00
abstract::Aspartate aminotransferase (AspAT) isozymes from Eleusine coracana (an NAD-malic enzyme type C4 plant) were examined. Three groups of isoenzymes were identified (AspAT-1, AspAT-2, and AspAT-3). AspAT-1 (localized in the mesophyll cells) and AspAT-3 (localized in the bundle sheath cells), both of which are considered t...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(90)90139-p
更新日期:1990-11-01 00:00:00
abstract::The acute effect of ethanol on hepatic protein synthesis is a rather controversial issue. In view of the conflicting reports on this subject, the effect of ethanol on protein labeling from L-[3H]valine in isolated liver cells was studied under a variety of experimental conditions. When tracer doses of the isotope were...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(83)90269-2
更新日期:1983-10-01 00:00:00
abstract::The murine macrophage (M phi) cell line, P388D1, was employed as a source of M phi phospholipases in order to characterize the enzymatic properties and subcellular localization of these enzymes because of their importance for prostaglandin biosynthesis. Phospholipase activity was assessed with dipalmitoylphosphatidylc...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(85)90162-6
更新日期:1985-04-01 00:00:00
abstract::Peroxisomes were isolated from AS-30D hepatoma and compared to normal rat liver cells for the purpose of investigating the cholesterol accumulation in the hepatoma cells. Cholesterol was found to be approximately 10-fold higher relative to protein in AS-30D peroxisomes as compared to peroxisomes from normal liver. The...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(91)90355-m
更新日期:1991-03-01 00:00:00
abstract::The plant-derived flavonoid, quercetin (QCT), has many biological actions, including cardioprotective actions, resulting from its antioxidant and anti-inflammatory effects. In this study, effects of QCT and its metabolites on the contraction and Ca2+ transients (CaT) of mouse single cardiomyocytes were simultaneously ...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/j.abb.2017.11.009
更新日期:2018-01-01 00:00:00
abstract::We explored furin substrate requirements in addition to the motif R-X-K/R-R using synthetic fluorescent resonance energy transfer (FRET) decapeptides. These decapeptides were derived from furin cleavage sites in viral coat glycoproteins and human and bacterial protein precursors. The hydrolysis by furin of most substr...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/j.abb.2009.05.013
更新日期:2009-07-15 00:00:00
abstract::Rat liver microsomes catalyze a vanadate-stimulated oxidation of NAD(P)H, which is augmented by paraquat and suppressed by superoxide dismutase, but not by catalase. NADPH oxidation was a linear function of the concentration of microsomes in the absence of vanadate, but was a saturating function in the presence of van...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(86)90710-1
更新日期:1986-10-01 00:00:00
abstract::5-Epi-aristolochene synthase is a sesquiterpene cyclase activity found in pathogen-challenged tobacco cells, but not in nonchallenged tissues, and appears to be encoded by a complex gene family. As a prerequisite to assessing the functional significance of these multiple genes, bacterial expression systems were examin...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.1994.1533
更新日期:1994-12-01 00:00:00
abstract::Phosphatidylserine (PS) is predominantly confined to the inner leaflet of plasma membrane in cells, but it is externalized on the cell surface during apoptosis. This externalized PS is required for effective phagocytosis of apoptotic cells by macrophages. Because PS trans-bilayer asymmetry is not absolute in different...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/s0003-9861(03)00083-3
更新日期:2003-05-01 00:00:00
abstract::An inhibitor protein of the catalytic subunit of the cyclic 3',5'-AMP-dependent protein kinase from the nematode Ascaris suum was isolated and characterized. The molecular weight of the inhibitor was estimated as 28,000 by electrophoresis under denaturing conditions and as 30,000 by gel permeation chromatography on Su...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(92)90676-n
更新日期:1992-09-01 00:00:00