Abstract：
:The reaction by which the antioxidant capacity of alpha-tocopherol is sustained by recycling of the alpha-tocopheroxyl radical in membranes or lipoproteins by aqueous ascorbate has been studied by laser flash photolysis in model micellar and membrane systems. In bilayers of dimyristoylphosphatidylcholine at 35 degrees C the measured second-order rate constant was 3 x 10(5) M s-1, or about five times slower than previously reported in a solvent system. The rate of reaction was decreased on addition of negatively charged lipid (dipalmitoylphosphatidic acid) and increased by addition of positively charged lipid (didodecyldimethylammonium bromide). These effects of bilayer charge were suppressed by increasing the ionic strength of the aqueous medium. Micellar charge also had an effect on the pH dependence of the reaction rate. Arrhenius data showed that the enthalpy of activation was effectively zero for the reaction in solution between ascorbate and radicals of water-soluble tocopherol analogues, but was positive in membrane and micellar systems. In all cases the entropy of activation was strongly negative. The kinetic deuterium isotope ratio varied between 3 and 8. The data strongly support a concerted electron and proton transfer mechanism for the reaction between alpha-tocopheroxyl radical and ascorbate.
journal_name
Arch Biochem Biophysjournal_title
Archives of biochemistry and biophysicsauthors
Bisby RH,Parker AWdoi
10.1006/abbi.1995.1150subject
Has Abstractpub_date
1995-02-20 00:00:00pages
170-8issue
1eissn
0003-9861issn
1096-0384pii
S0003-9861(85)71150-2journal_volume
317pub_type
杂志文章abstract：:Prostasomes are membranous vesicles (150-200 nm diameter) present in human semen. They are secreted by the prostate gland and contain large amounts of cholesterol, sphingomyelin, and Ca2+. In addition, some of their proteins are enzymes. Prostasomes enhance the motility of ejaculated sperm and are involved in a number...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1997.9999
更新日期：1997-07-01 00:00:00
abstract：:Much of what is known about the antioxidant mechanism of vitamin E has been learned from studies of lipid dispersions, solutions, or subcellular organelles. We have investigated the effect of vitamin E supplementation on intact live eucaryotic cells. L1210 murine leukemia cells were exposed to an oxidative stress indu...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1996.0454
更新日期：1996-10-15 00:00:00
abstract：:Just 25 years ago the Anfinsen thermodynamic hypothesis was shown to be valid for membrane proteins. Despite the complex biological machinery required for their in vivo assembly and in face of the chemically heterogeneous, anisotropic nature of their biological lipid bilayer "solvent", the evidence continues to sugges...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章,评审
doi：10.1016/j.abb.2007.09.024
更新日期：2008-01-01 00:00:00
abstract：:Green tea (Camellia sinensis) is rich in catechins, of which (-)-epigallocatechin-3-gallate (EGCG) is the most abundant. Studies in animal models of carcinogenesis have shown that green tea and EGCG can inhibit tumorigenesis during the initiation, promotion and progression stages. Many potential mechanisms have been p...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章,评审
doi：10.1016/j.abb.2010.06.013
更新日期：2010-09-01 00:00:00
abstract：:Rat transferrin (rTf), containing one complex glycan, and human transferrin (hTf), containing two complex glycans, were treated with peptide:N-glycosidase F (PNGase) under nondenaturing conditions. Apo rTf with a nonfucosylated standard biantennary glycan, but not its diferric counterpart, yielded satisfactory amounts...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(89)90331-7
更新日期：1989-02-01 00:00:00
abstract：:In an effort to model the interaction of lipid-based DNA delivery systems with anionic surfaces, such as a cell membrane, we have utilized microelectrophoresis to characterize how electrokinetic measurements can provide information on surface charge and binding characteristics. We have established that cationic lipids...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1999.1201
更新日期：1999-06-01 00:00:00
abstract：:Plant polyphenols are extremely diverse, due to the occurrence of several basic structures, numerous substitutions and, for some groups, of polymers (tannins). Plant polyphenol composition depends on the plant species and organ, with some molecules specific of particular plant families while others are ubiquitous. The...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章,评审
doi：10.1016/j.abb.2010.03.018
更新日期：2010-09-01 00:00:00
abstract：:Macrophages play a pivotal role in the defense response against harmful pathogens and stimuli by releasing various pro-inflammatory mediators. However, overproduction of pro-inflammatory mediators will do harm to the organism and cause inflammation-associated diseases. Omentin-1, which is a newly discovered adipokine,...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2019.108187
更新日期：2020-01-15 00:00:00
abstract：:Phosphofructokinase was purified from muscle tissue of two different molluscs, edible snails, Helix pomatia (gastropoda), and mussels, Mytilus edulis (bivalvia). Under denaturing conditions, both enzymes had a molecular mass of 82 kDa. In the presence of ATP-Mg2+, the enzymes were rapidly phosphorylated in vitro by th...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(91)90477-z
更新日期：1991-06-01 00:00:00
abstract：:Glycosylasparaginase (EC 3.5.1.26) is a lysosomal amidase which hydrolyzes the bond between asparagine and the sugar moiety in N-linked glycoproteins. Deficiency of the enzyme results in aspartylglycosaminuria (AGU), the most common disorder of glycoprotein degradation. Mature enzyme is formed by two proteolytic cleav...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1996.0144
更新日期：1996-04-01 00:00:00
abstract：:XynA from Erwinia chrysanthemi (EcXyn30A), belonging to glycoside hydrolase family 30 subfamily 8, is specialized for hydrolysis of 4-O-methylglucuronoxylan (GX). Carboxyl group of 4-O-methylglucuronic acid serves as a substrate recognition element interacting ionically with positively charged Arg293 of the enzyme. We...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2018.02.014
更新日期：2018-04-02 00:00:00
abstract：:Two new types of bacterial Fe-S L-serine dehydratases have been identified. These join two previously recognized enzyme types, for a total of four, that are distinguished on the basis of domain arrangement and amino acid sequence. A Type 3 enzyme from Amphibacillus xylanus (axLSD) and a Type 4 enzyme from Heliscomenob...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2013.10.009
更新日期：2013-12-01 00:00:00
abstract：:Human plasma glutathione peroxidase was purified to homogeneity and partially sequenced. Overlapping peptide fragments from three endopeptidase digests permitted the determination of one sequence of 32 contiguous amino acids and one sequence of 23 contiguous amino acids. Five additional unique peptide sequences withou...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(91)90048-n
更新日期：1991-05-01 00:00:00
abstract：:cDNA clones encoding NADP(+)-glyceraldehyde-3-phosphate dehydrogenase (NADP(+)-GAPDH) and sedoheptulose-1,7-bisphosphatase (SBPase) were isolated and characterized from halotolerant Chlamydomonas sp. W80 (C. W80) cells. The cDNA clone for NADP(+)-GAPDH encoded 369 amino acid residues, preceded by the chloroplast trans...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.2001.2375
更新日期：2001-06-15 00:00:00
abstract：:A peptide containing 43 amino acid residues, rich in glutamic acid and lysine, was originally isolated from calf thymus and designated thymosin beta 4 [T.L.K. Low, S. -K. Hu, and A. L. Goldstein (1981) Proc. Nat. Acad. Sci. USA 78, 1162-1166]. However, thymosin beta 4 was also shown to be present in other tissues of r...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(83)90177-7
更新日期：1983-03-01 00:00:00
abstract：:We have found for the first time that a chromosomal gene, mlr6807, in Mesorhizobium loti encodes a new tetrameric pyridoxal 4-dehydrogenase (PLDH). The recombinant enzyme expressed in Escherichia coli cells was homogenously purified and characterized. The enzyme consisted of four subunits each with a molecular weight ...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2006.06.002
更新日期：2006-08-01 00:00:00
abstract：:The mechanisms by which sterols and nonsterols regulate hepatic 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase gene expression was investigated by measuring mRNA, protein, and enzyme activity in rats fed cholesterol or given drugs that deplete both endogenous sterols and nonsterols or that selectively deple...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1994.1059
更新日期：1994-02-01 00:00:00
abstract：:Human sorcin, M(r) 22-kDa/pI 5.3, was identified in HOB1 lymphoma cells resistant to 1.0 microM vincristine and polyclonal antibody against it was produced. Using antibody to precipitate sorcin from 32P-labeled cell extract, the SDS-PAGE-resolved human sorcin was not phosphorylated in contrast to the report of A. M. v...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1996.0027
更新日期：1996-01-15 00:00:00
abstract：:Much effort has focused on the identification of MAPK cascades that are activated by the MEKK family of protein kinases. However, direct phosphorylation and regulation of the MEKK proteins has not been shown. To address this question, we have expressed recombinant (His)6FLAG.MEKK3 in Sf9 insect cells and tethered the ...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/s0003-9861(02)00464-2
更新日期：2002-11-01 00:00:00
abstract：:It is widely accepted that the function of human renalase is to oxidize catecholamines in blood. However, this belief is based on experiments that did not account for slow, facile catecholamine autoxidation reactions. Recent evidence has shown that renalase has substrates with which it reacts rapidly. The reaction cat...
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
abstract：:The effects of testosterone propionate (TP) on the oxidative stress and mitochondrial function, as well as on mitochondria associated apoptotic signaling, were analyzed in the gastric mucosa in orchiectomized male rats. The present study showed that testosterone deficiency triggered apoptosis by damaging the mitochond...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2018.05.002
更新日期：2018-07-01 00:00:00
abstract：:The reduction of duroquinone (DQ), 2,3-dimethoxy-5-methyl-6-decyl-1,4-benzoquinone (DB), and dichlorophenol indophenol (DCIP) by succinate and NADH was investigated in yeast mitochondria which have no spectrally detectable cytochrome b. Succinate reduces DB in the cytochrome b-deficient mitochondria at rates comparabl...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(88)90148-8
更新日期：1988-09-01 00:00:00
abstract：:Purified NAD-malic enzyme from Ascaris suum is rapidly inactivated by the arginine reagent, 2,3-butanedione, and this inactivation is facilitated by 30 mM borate. Determination of the inactivation rate as a function of butanedione concentration suggests a second-order process overall, which is first order in butanedio...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(87)90288-8
更新日期：1987-05-15 00:00:00
abstract：:Adriamycin (AdM) and related anthracyclines are potent antineoplastic agents, the clinical utility of which is limited by severe cardiotoxicity. Aglycone derivatives of AdM have recently been reported to trigger the release of Ca2+ from isolated, preloaded rat heart mitochondria and to modify mitochondrial sulfhydryl ...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(91)90298-w
更新日期：1991-02-01 00:00:00
abstract：:The relationship between erythroid delta-aminolevulinate (ALA) synthase and hepatic ALA synthase in rat was analyzed immunochemically, using antibodies directed against rat liver ALA synthase and against chicken liver ALA synthase. Rat erythroid ALA synthase showed no cross-reactivity with anti-liver ALA synthase anti...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(86)90191-8
更新日期：1986-02-15 00:00:00
abstract：:Treatment of human pulmonary artery smooth muscle cells (HPASMCs) with the thromboxane A2 receptor antagonist, SQ29548 inhibited U46619 stimulation of phospholipase D (PLD) and NADPH oxidase activities in the cell membrane. Pretreatment with apocynin inhibited U46619 induced increase in NADPH oxidase activity. The cel...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2017.08.012
更新日期：2017-11-01 00:00:00
abstract：:Calycosin, a functional phytoestrogen isoflavone isolated from Radix astragali, has been shown to possess multiple pharmacological properties including anti-cancer activity. However, up to now, the anti-cancer effect and the related mechanism of calycosin on cervical cancer (CC) cells have not been explored. It has be...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2020.108478
更新日期：2020-09-30 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：:A search of the chicken expressed sequence tag (EST) database identified 2 cDNA clones that appeared to represent members of the SULT1B and SULT1C enzyme families. These cDNAs were fully sequenced and found to contain full-length inserts. Phylogenetic analysis of the derived amino acid sequences clearly placed them as...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2004.05.008
更新日期：2004-08-01 00:00:00
abstract：:Functional activities of isolated atria from 4-week diabetic rats and their anoxic tolerance and recovery were compared to those of control rats. The present study showed a two-fold increase in maximum developed contraction force (CF), the rate of force development, and the rate of relaxation in isolated atria from di...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(90)90479-i
更新日期：1990-05-15 00:00:00
