Abstract：
:In the presence of rat liver cytosol and homocysteine, trimethylselenonium ion (TMSe+) underwent time-dependent demethylation to dimethylselenide with the concurrent formation of methionine. Convenient methods were developed for assay of this activity using either radioactive methods based on the gamma emitting isotope 75Se or nonradioactive HPLC assay of methionine. The rate of demethylation was linear with protein concentration and dependent on homocysteine, which could not be replaced by cysteine, glutathione, or dithiothreitol. The TMSe+ demethylation rate was inhibited by the addition of betaine, sulfobetaine (dimethylthetin), or dimethylglycine. The Km for TMSe+ was 8 mM compared to 0.04 mM for betaine, but the rate of TMSe+ demethylation was approximately 50-fold that of betaine when both were assayed at 25 mM. Methionine was also produced from selenobetaine, selenobetaine methylester, and sulfobetaine. The selenium analogues of betaine inhibited the demethylation of TMSe+ with only minor decreases in methionine production, indicating substrate competition. In preliminary studies aimed at the partial purification of the TMSe+:homocysteine methyltransferase activity, the enzyme was found to have chromatographic and heat stability characteristics similar to betaine:homocysteine methyltransferase. The data indicate that betaine:homocysteine methyltransferase, or a very similar enzyme, is involved in the demethylation of TMSe+ and show that TMSe+, an in vivo urinary selenium metabolite of many selenium compounds, is not biologically inert.
journal_name
Arch Biochem Biophysjournal_title
Archives of biochemistry and biophysicsauthors
Goeger DE,Ganther HEdoi
10.1006/abbi.1993.1203subject
Has Abstractpub_date
1993-04-01 00:00:00pages
222-7issue
1eissn
0003-9861issn
1096-0384pii
S0003-9861(83)71203-8journal_volume
302pub_type
杂志文章abstract：:The effects of in vitro addition of halogenated hydrocarbons on the susceptibility of various rat tissues to lipid peroxidation, and of iron overload and dietary vitamin E in the intact rat on subsequent lipid peroxidation in rat tissue slices were examined. The ease and speed of tissue slice preparation allowed testi...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(84)90502-2
更新日期：1984-09-01 00:00:00
abstract：:Phospholipid transfer protein catalyzes the transfer of phospholipids between bilayer membranes. A general model is developed for describing the kinetics of this process. While previous models derive detailed expressions only for the initial rate of transfer from donor to acceptor membranes, this model takes into acco...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(88)90262-7
更新日期：1988-11-01 00:00:00
abstract：:Electron spin lattice relaxation times (T1) and the phase memory times (Tm) were obtained for the synthetic melanin system from 3-hydroxytyrosine (dopa) by means of electron spin echo spectroscopy at 77 degrees K. Saturation behavior of the ESR spectra of melanins in melanin-containing tissue and of the synthetic mela...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(85)90493-x
更新日期：1985-10-01 00:00:00
abstract：:Heparin infusion in an experimental animal model of arterial injury causes a significant increase in the proteoglycan (PG) component of the extracellular matrix in the injured arteries (Snow, A. D., Bolender, R. P., Wight, T. N., and Clowes, A. W. (1990) Am. J. Pathol. 137, 313-330). The mechanisms responsible for thi...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1996.0527
更新日期：1996-12-01 00:00:00
abstract：:In recent years there has been much interest in the role that products of carotenoid breakdown--the norisoprenoids--may play in wine aroma. The basis for this interest is that norisoprenoids have very low olfactory perception thresholds and so have a high sensorial impact on wine aroma. The norisoprenoids can be forme...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章,评审
doi：10.1016/j.abb.2009.01.008
更新日期：2009-03-15 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：:The nonenzymatic reaction of the cytotoxic compounds menadione (2-methyl-1,4-naphthoquinone) and 1,4-naphthoquinone (a reactive metabolite of 1-naphthol) with reducing agents such as NADPH and glutathione led to the formation of semiquinone-free radicals, which were detected with electron spin resonance spectroscopy. ...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(87)90006-3
更新日期：1987-01-01 00:00:00
abstract：:It has previously been found that there is a synergistic effect of free purine bases and low concentrations of dialyzed platelet extract on net synthesis of DNA in serum-starved fibroblast-like mouse L-cells. Experiments with a mutant line of L-cells that was deficient in hypoxanthine phosphoribosyl transferase (EC 2....
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(85)90699-x
更新日期：1985-06-01 00:00:00
abstract：:The susceptibility of 40S and 60S ribosomal subunits from Saccharomyces cerevisiae to digestion with varying concentrations of trypsin was studied by two-dimensional electrophoresis and quantitative measurements of the protein remaining with the ribosomal particles after trypsin treatment. Proteins from both subunits ...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(83)90190-x
更新日期：1983-07-01 00:00:00
abstract：:1-O-Alkyl-2-acetyl-sn-glycero-3-phosphocholine (AGEPC) induced phosphorylation of two proteins having molecular masses of approximately 20- and 40-kDa in washed rabbit platelets in a concentration- and time-dependent manner. Sequential stimulation with AGEPC did not induce additional protein phosphorylation, supportin...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(86)90342-5
更新日期：1986-05-01 00:00:00
abstract：:Vascular smooth muscle cell (VSMC) proliferation is a key event in the progression of atherosclerosis. Induction of both c-fos (through the transcription factor Elk-1) and c-jun, both immediate early genes, is important for the stimulation of VSMC proliferation and migration. It was earlier found that p38 mitogen-acti...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/S0003-9861(02)00028-0
更新日期：2002-04-15 00:00:00
abstract：:The rate constant for quenching, kq, of the phosphorescence of 6-bromo-2-naphthyl sulfate (BNS) by cytochromes c, cytochrome c peroxidase, catalase, and myoglobin has been measured as a function of temperature and solvent viscosity. In aqueous solution at pH 7.0 for cytochromes c and myoglobin the value of kq is nearl...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1994.1190
更新日期：1994-05-01 00:00:00
abstract：:Most transcription factors are believed to bind promoter elements in the B-DNA conformation, wherein linear sequence determines specificity. However, there are promoter elements that can form complex structures such as intramolecular triplexes, and these structures may participate in the activity of these promoter ele...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1994.1162
更新日期：1994-04-01 00:00:00
abstract：:Arachidonate 12-lipoxygenase (12-LO) from porcine leukocytes was expressed in insect cells using a baculovirus expression vector. The recombinant 12-LO was expressed as an N-terminal fusion protein with a 31-amino acid polypeptide carrying a six-histidine tag and an enterokinase cleavage site. Maximal intracellular en...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1994.1302
更新日期：1994-07-01 00:00:00
abstract：:Characterization of aldose reductase purified from human placenta confirms that activation, as first analyzed in detail for the bovine enzyme, also occurs in humans. Routinely between 5 and 20% of the aldose reductase activity freshly purified from human placenta exhibits kinetic properties and insensitivity to aldose...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1996.0096
更新日期：1996-03-01 00:00:00
abstract：:A new creatine analog, 1-carboxyethyl-2-iminoimidazolidine (homocyclocreatine), has been synthesized and compared with other synthetic analogs of creatine as a substrate for creatine kinase under both in vitro and in vivo conditions. Reactivity with rabbit muscle creatine kinase at 2 mM and pH 7.0 occurred in the orde...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(83)90448-4
更新日期：1983-02-01 00:00:00
abstract：:The role of the conserved sequence motif 301DDLTDP306 in the F0F1 ATP synthase beta subunit was assessed by mutagenic analysis in the Escherichia coli enzyme. Mutations gave variable effects on F1 sector activity, stability, and membrane binding to the F0 sector. Upon solubilization, F1 sectors of the betaD302E and be...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1998.0856
更新日期：1998-10-15 00:00:00
abstract：:The ability of chelators and ascorbic acid to mobilize iron from crocidolite, amosite, medium- and short-fiber chrysotile, and tremolite was investigated. Ferrozine, a strong Fe(II) chelator, mobilized Fe(II) from crocidolite (6.6 nmol/mg asbestos/h) and amosite (0.4 nmol/mg/h) in 50 mM NaCl, pH 7.5. Inclusion of asco...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(90)90231-m
更新日期：1990-04-01 00:00:00
abstract：:G protein-coupled receptors can be directly modulated by changes in transmembrane voltage in a variety of cell types. Here we show that, while changes in the membrane voltage itself do not induce detectable modifications in the cytosolic Ca(2+) concentration, platelet stimulation with thrombin or the PAR-1 and PAR-4 a...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2013.08.007
更新日期：2013-10-15 00:00:00
abstract：:An increased permeability of the intestinal barrier is proposed as a major event in the pathophysiology of inflammatory bowel diseases (IBD). Tumor necrosis alpha (TNFα) plays a central role in IBD pathogenesis, in part promoting tight function (TJ) barrier dysfunction. Food extracts enriched in (-)-epicatechin (EC) p...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2015.01.024
更新日期：2015-05-01 00:00:00
abstract：:The hnRNP A/B family contains abundant nuclear proteins with major roles in alternative splicing and the ability for nucleo-cytoplasmic shuttling. Compared to the best known members of this family (hnRNP A1, A2/B1), hnRNP A3 is a relatively less known protein. We report herein immunochemical studies with the hnRNP A3 ...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2012.04.012
更新日期：2012-07-15 00:00:00
abstract：:Carbamoyl phosphate synthetase I (CPSase I) catalyzes the first reaction of the urea cycle in mammalian ureotelic species. The positive allosteric cofactor N-acetyl-L-glutamate (AGA) is required for CPSase I activity and is important for regulation of the urea cycle. A similar enzyme, CPSase III, catalyzes this reacti...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1997.0511
更新日期：1998-02-01 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：:Maitotoxin (MTX) is a highly potent marine toxin that activates both voltage-sensitive and receptor-operated calcium channels in the plasma membrane. This results in calcium overload that rapidly leads to cell death. We now report that maitotoxin (0.1-1 nM) induces calpain activation in both SH-SY5Y neuroblastoma cell...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1996.0300
更新日期：1996-07-15 00:00:00
abstract：:In this study we related metacarb (N-(2-(3,5-bis(dimethylcarbamoyloxy)phenyl)-2-hydroxyethyl)propan-2-aminium chloride) and isocarb (N-(2-(3,4-bis(dimethylcarbamoyloxy)phenyl)-2-hydroxyethyl)propan-2-aminium chloride) inhibition selectivity, as well as stereoselectivity of mouse acetylcholinesterase (AChE; 3.1.1.7) an...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2012.11.012
更新日期：2013-01-15 00:00:00
abstract：:The cellulose synthase protein (AcsAB) is encoded by a single gene in Gluconacetobacter hansenii ATCC 23769. We have examined the processing pattern of this enzyme and the localization of the cleavage products by heterologously expressing the truncated portions of the AcsAB protein and using specific antibodies genera...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2012.12.002
更新日期：2013-01-15 00:00:00
abstract：:Two enzymatically modified derivatives of tobramycin have been prepared by gentamicin nucleotidyl transferase-catalyzed adenylylation of tobramycin, using ATP and (Sp)-ATP alpha S as adenylylation substrates. (EC 2.7.7.46). The 1H, 13C, and 31P NMR spectra have been assigned for tobramycin, 2''-(adenosine-5'-phosphory...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(90)90331-r
更新日期：1990-08-01 00:00:00
abstract：:The NCI-H69 cell alpha 1----3fucosyltransferase has been purified from a 0.2% Triton X-100R solubilized enzyme fraction by GDP-hexanolamine-Sepharose affinity chromatography and Superose 12 gel filtration. Photoaffinity labeling experiments with 125I-GDP-hexanolaminyl-4-azidosalicylic acid present in concentrations eq...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(92)90611-y
更新日期：1992-08-01 00:00:00
abstract：:Carbohydrate response element binding protein (ChREBP) is a transcription factor that activates liver glycolytic and lipogenetic enzyme genes in response to high carbohydrate diet. Here we report the transcriptional regulatory mechanisms for the rat ChREBP gene. Firstly, we determined the transcription initiation site...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2007.02.028
更新日期：2007-05-01 00:00:00
abstract：:The actions of polycyclic aromatic hydrocarbons and glucocorticoids to regulate the expression of cytochrome P450c were investigated using cultured fetal rat hepatocytes. Cytochrome P450c mRNA content, determined by Northern blot analysis, was induced in cells treated with 1,2-benzanthracene from levels undetectable i...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(89)90090-8
更新日期：1989-02-15 00:00:00
