Abstract:
:The pH dependencies of both the forward and reverse orotate phosphoribosyltransferase (ORPTase)-catalyzed reactions have been examined and determined to be dissimilar, with maximal activity for the forward reaction near to pH 8. The maximal activity of the reverse pyrophosphorolysis was observed between pH 6.5 and 7.5. Appropriate pK values were determined using computer fitting exercises. One such pK value (equal to 8.6) suggested the presence of lysine residues at the OPRTase active site. Incubations of OPRTase with the substrate analog, uracil 6-aldehyde, in the presence of sodium borohydride, suggested that this compound is a covalent modifier of OPRTase lysine residues, and substrate protection studies provided evidence that the affected lysine residues were located near to both the phosphoribosyl 1-pyrophosphate (PRibPP) and the orotate binding sites. Similar studies with pyridoxal 5-phosphate and labeled sodium borohydride as modifiers have revealed that two modified active site lysine residues per OPRTase subunit account for the loss of 90% of the enzymatic activity with this reagent. We suggest that essential lysine residues, along with divalent metal ions, are located at the OPRTase active site, and form ion-pair bonds with anionic PRibPP and orotate as these substrates bind to the enzyme. We also report that 5-azaorotate is an alternate substrate for OPRTase (Km = 75.5 +/- 0.1 microM) leading to formation of an unstable nucleotide product).
journal_name
Arch Biochem Biophysjournal_title
Archives of biochemistry and biophysicsauthors
Ashton RW,Strauss RS,Chung SH,Sloan DLdoi
10.1016/0003-9861(89)90236-1subject
Has Abstractpub_date
1989-08-01 00:00:00pages
421-32issue
2eissn
0003-9861issn
1096-0384pii
0003-9861(89)90236-1journal_volume
272pub_type
杂志文章abstract::Endothelial senescence is the main risk factor that contributes to vascular dysfunction and the progression of vascular disease. Carbon monoxide (CO) plays an important role in preventing vascular dysfunction and in maintaining vascular physiology or homeostasis. The application of exogenous CO has been shown to confe...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/j.abb.2019.108185
更新日期:2019-11-30 00:00:00
abstract::Cellular glutathione is released during apoptosis and may play a role in the regulation of the mitochondrial permeability transition pore. The question of whether only cytosolic glutathione is important in apoptosis, or whether mitochondrial glutathione also plays a role, was investigated using gamma-glutamyltranspept...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.2001.2662
更新日期:2002-01-15 00:00:00
abstract::Reduction-oxidation (redox) response is one of the most important biological phenomena. The concept introduced by Helmut Sies encouraged many researchers to examine oxidative stress under pathophysiological conditions. Our group has been interested in redox regulation under oxidative stress as well as glycobiology in ...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/j.abb.2015.11.024
更新日期:2016-04-01 00:00:00
abstract::The role of fatty acid metabolism in chemical-dependent cell injury is poorly understood. Addition of L-carnitine to the incubation medium of cultured hepatocytes delayed cell killing initiated by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Protection by L-carnitine was stereospecific and observed as late as ...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(90)90019-u
更新日期:1990-01-01 00:00:00
abstract::Acidithiobacillus ferrooxidans sulfide:quinone oxidoreductase (SQR) catalyzes the oxidation of sulfide to polysulfide chains or elemental sulfur coupled to quinone reduction via a non-covalent FAD cofactor. We investigated the role of the FAD using kinetics and EPR spectroscopy. The properties of the enzyme were compa...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/j.abb.2014.09.016
更新日期:2014-12-15 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::Cytochromes P450 are enzymes that catalyse the oxidation of a wide variety of compounds that range from small volatile compounds, such as monoterpenes to larger compounds like steroids. These enzymes can be modified to selectively oxidise substrates of interest, thereby making them attractive for applications in the b...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/j.abb.2019.07.025
更新日期:2019-09-15 00:00:00
abstract::L-ribulokinase is unusual among kinases since it phosphorylates all four 2-ketopentoses with almost the same k(cat) values. The K(m)'s differ, however, being 0.14 mM for L- and 0.39 mM for d-ribulose and 3.4 mM for l- and 16 mM for d-xylulose. In addition, L-arabitol is phosphorylated at C-5 (K(m) 4 mM) and ribitol (a...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.2001.2613
更新日期:2001-12-15 00:00:00
abstract::There is evidence to suggest that extracellular matrix molecules, such as proteoglycans, are involved in the regulation of mineral deposition in calcifying tissues. One mineralizing system which is characterized by extremely rapid mineralization is the hen eggshell. This eggshell consists of a pair of nonmineralized e...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(92)90126-h
更新日期:1992-10-01 00:00:00
abstract::Previous work from this laboratory indicated that the N-terminus of recombinant human cytochrome P450 (P450) 1A2 expressed in Escherichia coli is blocked (P. Sandhu, Z. Guo, T. Baba, M. V. Martin, R. H. Tukey, and F. P. Guengerich, (1994) Arch. Biochem. Biophys. 30, 168 -177). A modification of this construct was done...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.1996.0086
更新日期:1996-03-01 00:00:00
abstract::Selenoprotein I (SELENOI) is an ethanolamine phosphotransferase that catalyzes the third reaction of the Kennedy pathway for the synthesis of phosphatidylethanolamine. Since the role of SELENOI in murine embryogenesis has not been investigated, SELENOI-/+ mating pairs were used to generate global KO offspring. Of 323 ...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/j.abb.2020.108444
更新日期:2020-08-15 00:00:00
abstract::Rabbit muscle glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was inactivated by peroxynitrite under biologically relevant conditions. The decrease of enzymatic activity followed an exponential function, and the concentration of peroxynitrite needed to inactivate 50% of 7 microM GAPDH (IC50) was 17 microM. Hydroxyl r...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.1998.0932
更新日期:1998-12-15 00:00:00
abstract::Myelin basic protein is known to be released into the circulation following traumatic injuries or demyelination within the central nervous system, resulting in the generation of potentially immunogenic myelin basic protein material. In this investigation we have studied the binding of bovine and human myelin basic pro...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.1998.0902
更新日期:1998-11-15 00:00:00
abstract::MicroRNA-885 (miR-885) has been shown to act as vital regulator of tumorigenesis and its tumor-suppressive role has been investigated in several human cancers. However, the role of miR-885 in regulation of epithelial mesenchymal transition of liver cancer cells yet unknown. This study was undertaken to investigate the...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/j.abb.2020.108588
更新日期:2020-10-30 00:00:00
abstract::Using proton NMR, the solution conformation of the A ring of vitamin D3 and its analogs has been studied by application of the Karplus relation to the observed coupling constants. The A-ring conformations of vitamins D3, D2, and 25-hydroxyvitamin D3 were found to be solvent dependent, with a clear preference for an eq...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(85)90587-9
更新日期:1985-09-01 00:00:00
abstract::An inhibitor of the transforming growth factor-induced growth in soft agar of normally anchorage-dependent rat kidney fibroblasts has been detected in the acid-ethanol extracts of human placenta, bovine lung and kidney, and human rhabdomyosarcoma cells (A673). The inhibitor has been purified from human placenta by gel...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(84)90089-4
更新日期:1984-04-01 00:00:00
abstract::Isolated mitochondria loaded with Ca(2+) and then exposed to Fe(2+) show a transient release of Ca(2+). The magnitude of this response depends on the Ca(2+) loading and the kinetics of the response depends on the concentration of added Fe(2+). We investigated the Fe(2+)-induced Ca(2+) release mechanism by measuring mi...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.2001.2721
更新日期:2002-02-15 00:00:00
abstract::The keto form of oxaloacetate (OAA), a product of phosphoenolpyruvate carboxylase (PEPC) activity, can undergo various nonenzymatic conversions which make conventional methods of assaying the enzyme difficult, because the products may either act as inhibitors or go undetected. In studies with PEPC isolated from leaves...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(86)90502-3
更新日期:1986-08-01 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
abstract::The interconversion of mannose-6-P and mannose-1-P in brain has been shown to be catalyzed by a distinct enzyme. The enzyme has been separated from most of the phosphoglucomutase activity of the brain. The residual phosphoglucomutase activity (less than 1%) may be associated with phosphomannomutase itself. Mannose-1,6...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(85)90785-4
更新日期:1985-11-15 00:00:00
abstract::The Oxidative Stress Theory of Aging has had tremendous impact in research involving aging and age-associated diseases including those that affect the nervous system. With over half a century of accrued data showing both strong support for and against this theory, there is a need to critically evaluate the data acquir...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章,评审
doi:10.1016/j.abb.2015.01.029
更新日期:2015-06-15 00:00:00
abstract::A marine snail digestive phospholipase A2 (mSDPL) was purified from delipidated hepatopancreas. Unlike known digestive phospholipases A2, which are 14 kDa proteins, the purified mSDPL has a molecular mass of about 30 kDa. It has a specific activity of about 180 U/mg measured at 50 degrees C and pH 8.5 using phosphatid...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/j.abb.2009.11.020
更新日期:2010-02-15 00:00:00
abstract::Uridine phosphorylase is one of the critical enzymes in the pyrimidine salvage pathway. Cells regenerate uridine for nucleotide metabolism by incorporating uracil with ribose-1-phosphate with this enzyme. Recent studies indicate that Escherichia coli uridine phosphorylase is destabilized in the presence of ATP. Howeve...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/j.abb.2017.09.007
更新日期:2017-11-15 00:00:00
abstract::The application of molecular dynamics simulations to study the folding and dynamics of peptides has attracted a lot of interest in the last couple of decades. Following the successful prediction of the folding of several proteins using molecular simulation, foldable peptides emerged as a favourable system mainly due t...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章,评审
doi:10.1016/j.abb.2019.01.033
更新日期:2019-03-30 00:00:00
abstract::TDP-43 is a nuclear protein whose abnormal aggregates are implicated in ALS and FTLD. Recently, an Asn/Gln rich C-terminal segment of TDP-43 has been shown to produce aggregation in vitro and reproduce most of the protein's pathological hallmarks in cells, but little is known about this segment's structure. Here, CD a...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/j.abb.2014.01.007
更新日期:2014-03-01 00:00:00
abstract::The presence of multiple proteases in the culture filtrate of Streptomyces moderatus was detected. After preliminary purification by ammonium sulfate precipitation and decolorization using DEAE-cellulose, the fractionation of various proteases was carried out using CM-trisacryl cation-exchange chromatography. By this ...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(87)90582-0
更新日期:1987-09-01 00:00:00
abstract::Recently, we synthesized and characterized vanadyl saccharides to evaluate the effects of various vanadate and vanadyl complexes, which differ in their oxidation states on various biomacromolecules and cellular activities (1, 2). Here, we report that both vanadate (+V oxidation state) and different vanadyl species (+I...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1006/abbi.1997.0394
更新日期:1998-01-01 00:00:00
abstract::A biochemical basis for the pea and lentil lectin resistance of two Chinese hamster ovary (CHO) cell mutants, Lec13 and Lec13A, was investigated. Studies of the G glycopeptides of vesicular stomatitis virus grown in the mutants indicated that Lec13 cells essentially lack the ability to add fucose to complex carbohydra...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(86)90031-7
更新日期:1986-09-01 00:00:00
abstract::An in vitro expression plasmid (pGRAP) that contained the cDNA coding for the rat mitochondrial aldehyde dehydrogenase precursor was constructed, mRNA was synthesized then translated, and the in vitro synthesized precursor of aldehyde dehydrogenase was used in an in vitro import assay. As expected the 19 amino acid si...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(89)90238-5
更新日期:1989-08-01 00:00:00
abstract::Conversion of geranyl pyrophosphate to cyclic monoterpenes is considered to involve the preliminary isomerization of this acyclic precursor to enzyme-bound linalyl pyrophosphate and the cyclization of this tertiary intermediate. 2-Fluorogeranyl pyrophosphate and 2-fluorolinalyl pyrophosphate are effective competitive ...
journal_title:Archives of biochemistry and biophysics
pub_type: 杂志文章
doi:10.1016/0003-9861(86)90390-5
更新日期:1986-12-01 00:00:00