Abstract:
:We studied the kinetic properties of the membrane-bound human liver mitochondrial protoporphyrinogen oxidase. The activity was monitored by direct recording of protoporphyrin fluorescence appearance in the incubation medium without extraction or dilution. The human liver enzyme shows some different catalytic properties than the rat enzyme since its optimum pH was found at 7.2. We also measured the optimum pH on partially purified protoporphyrinogen oxidase from solubilized human mitochondrial membranes. Like the rat enzyme, the human enzyme had a molecular weight of congruent to 32,000 as determined by gel filtration, but its optimum pH was the same as that of the membrane-bound enzyme. The apparent Km for protoporphyrinogen IX of the membrane-bound enzyme was a function of the pH; Km = 0.16 microM at pH 7.2, 0.33 microM at pH 8.0, and 0.55 microM at pH 8.5. Moreover, there was inhibition by excess protoporphyrinogen IX (KI = 5 microM at pH 7.2). The human enzyme was able to catalyze the oxidation of mesoporphyrinogen IX to mesoporphyrin IX. In this case, the Lineweaver-Burk plot of the data showed a biphasic curve with two different apparent Km's for mesoporphyrinogen IX of 0.5 microM (Vmax = 2.40 nmol h-1 mg-1) and 4 microM (Vmax = 5.7 nmol h-1 mg-1). Human liver protoporphyrinogen oxidase was sensitive to inhibition by some metalloporphyrins such as Mn- and Co-protoporphyrin, and to a lesser degree by Cd-, Ni- and Fe-protoporphyrin (heme). Cu-, Mg-, Sn-, and Zn-protoporphyrins were not inhibitors of the activity. A detailed study of the inhibition of protoporphyrinogen oxidase by cobalt-protoporphyrin shows a noncompetitive mechanism of inhibition with respect to protoporphyrinogen IX (KIapp = 0.8 microM).
journal_name
Arch Biochem Biophysjournal_title
Archives of biochemistry and biophysicsauthors
Camadro JM,Abraham NG,Levere RDdoi
10.1016/0003-9861(85)90494-1subject
Has Abstractpub_date
1985-10-01 00:00:00pages
206-12issue
1eissn
0003-9861issn
1096-0384pii
0003-9861(85)90494-1journal_volume
242pub_type
杂志文章abstract::Glucose-6-phosphatase is a multicomponent system located in the endoplasmic reticulum, involving both a catalytic subunit (G6PC) and several substrate and product carriers. The glucose-6-phosphate carrier is called G6PT1. Using light scattering, we determined K(D) values for phosphate and glucose transport in rat live...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/s0003-9861(02)00523-4
更新日期:2002-12-01 00:00:00
abstract::Neutrophils and monocytes produce the highly cytotoxic hypochlorous acid (HOCl) via the myeloperoxidase (MPO)-catalyzed reaction of H2O2 with Cl-. We have investigated the reaction of reagent and MPO-derived HOCl with cholesterol in a purified liposome system, as well as progressively more complex biological systems. ...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.1996.0317
更新日期:1996-08-01 00:00:00
abstract::The relationship between ligand-protein affinity and the extent of protein stabilization induced by such interactions has been investigated using the binding of polyanions to acidic fibroblast growth factor (aFGF) as a model system. It was found that the experimentally observed unfolding rate constant of aFGF consists...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.1994.1080
更新日期:1994-02-15 00:00:00
abstract::Troponin T (TnT) binds to tropomyosin (Tm) to anchor the troponin complex in the thin filament, and it thus serves as a vital link in the Ca(2+) regulation of striated muscle contraction. Pioneer work three decades ago determined that the T1 and T2 chymotryptic fragments of TnT each contains a Tm-binding site. A more ...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/j.abb.2010.06.001
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abstract::An in vitro acrosome-like reaction was induced in spermatozoa from the boar cauda epididymis by incubation in Tyrode's solution containing 1 mg/ml fatty acid-free bovine serum albumin. Plasma membranes were isolated from the spermatozoa at different times during the incubation and analyzed for their lipid composition....
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(86)90698-3
更新日期:1986-10-01 00:00:00
abstract::Estrogen-induced chick oviduct differentiation is accompanied by an increased capacity for protein glycosylation. A portion of this increase has been attributed to increased levels of dolichyl phosphate (Dol-P). Hormone withdrawal leads to an apparent decrease in Dol-P. Dol-P metabolism in the oviduct has been studied...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(84)90301-1
更新日期:1984-11-01 00:00:00
abstract::Transforming growth factor-beta (TGF-beta) reportedly induces vascular endothelial growth factor (VEGF) synthesis in osteoblast-like MC3T3-E1 cells. We have recently shown that TGF-beta activates p44/p42 mitogen-activated protein (MAP) kinase and p38 MAP kinase in these cells. In the present study, we investigated the...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/s0003-9861(03)00225-x
更新日期:2003-07-01 00:00:00
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journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/j.abb.2010.12.031
更新日期:2011-04-01 00:00:00
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journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.1996.0514
更新日期:1996-11-15 00:00:00
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journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(88)90348-7
更新日期:1988-03-01 00:00:00
abstract::Mammalian mitochondria are sensitive targets of the cytotoxic effects of superoxide (O.2-) and nitric oxide (.NO). In turn, when superoxide and nitric oxide are simultaneously produced, they rapidly react with each other yielding the highly oxidizing peroxynitrite anion (ONOO-) which may be also toxic to mammalian mit...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.1994.1013
更新日期:1994-01-01 00:00:00
abstract::The iodide oxidase activity and iodide-dependent pseudocatalatic activity of lignin peroxidase H2, an extracellular enzyme of the white rot fungus Phanerochaete chrysosporium, was inhibited by EDTA. The inhibition of iodide oxidase activity by EDTA was reversed at higher concentrations of iodide. Similar results were ...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.1993.1035
更新日期:1993-01-01 00:00:00
abstract::Adenylate cyclase activation by GTP and octopamine as well as basal activity (in the presence of Mg2+) have been studied as a function of membrane structure in plasma membranes from brain of the dipterous Ceratitis capitata. Benzyl alcohol and lidocaine, but not phenobarbital, inhibited the three activities to the sam...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(91)90085-w
更新日期:1991-05-01 00:00:00
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journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.1999.1159
更新日期:1999-05-01 00:00:00
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journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(85)90628-9
更新日期:1985-01-01 00:00:00
abstract::Fructose 2,6-bisphosphate inhibited all three fructose-1,6-bisphosphatases from the liver, intestine, and muscle of the mouse. The sensitivity of the liver enzyme to the inhibitor was significantly diminished when Mg2+ was replaced by Mn2+ as the activating cation. Inhibition of the liver enzyme by fructose 2,6-bispho...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(83)90292-8
更新日期:1983-10-01 00:00:00
abstract::This study characterizes the structural and functional significance of sulfhydryl residues in human plasma heparin cofactor II (HCII). For quantification of sulfhydryl groups, the extinction coefficient of HCII was redetermined and found to be 0.593 ml mg-1 cm-1 using second-derivative spectroscopy and multicomponent ...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(87)90499-1
更新日期:1987-12-01 00:00:00
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journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/j.abb.2008.07.011
更新日期:2008-09-15 00:00:00
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journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.1994.1323
更新日期:1994-08-01 00:00:00
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journal_title:Archives of biochemistry and biophysics
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doi:10.1016/j.abb.2005.05.015
更新日期:2005-07-15 00:00:00
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journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.1996.0430
更新日期:1996-10-01 00:00:00
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journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/j.abb.2015.05.016
更新日期:2015-08-01 00:00:00
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journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/j.abb.2004.05.018
更新日期:2004-09-01 00:00:00
abstract::The cardiomyopathy produced by the widely used anticancer drug adriamycin (ADR) is believed to be related to the production of reaction oxygen species and consumption of reduced glutathione (GSH) during redox cycling of the drug. Protection by vitamin E against the toxicity of ADR was studied in a model of compromised...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(87)90434-6
更新日期:1987-07-01 00:00:00
abstract::Chlorite dismutase-like proteins are structurally closely related to functional chlorite dismutases which are heme b-dependent oxidoreductases capable of reducing chlorite to chloride with simultaneous production of dioxygen. Chlorite dismutase-like proteins are incapable of performing this reaction and their biologic...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/j.abb.2015.01.010
更新日期:2015-05-15 00:00:00
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journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.1998.1087
更新日期:1999-03-15 00:00:00
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journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/j.abb.2004.08.010
更新日期:2004-12-01 00:00:00
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journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.1996.0257
更新日期:1996-06-15 00:00:00
abstract::The antioxidant, butylated hydroxytoluene (BHT), causes lung toxicity in mice followed by regenerative repair, and can also modulate the development of carcinogen-induced lung adenomas. We are investigating changes in pulmonary biochemistry following BHT treatment in order to understand the mechanisms of BHT-induced p...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(87)90421-8
更新日期:1987-07-01 00:00:00
abstract::This paper presents previously unobserved signals in the 1H NMR spectra of oxidized and reduced [2Fe-2S]-ferredoxin from Anabaena 7120 detected at 400, 500, and 600 MHz. The signals shifted to low field exhibited longitudinal relaxation (T1) values in the range of 100-400 microseconds and line widths in the range of 1...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(90)90289-b
更新日期:1990-05-01 00:00:00