Abstract：
:The multifunctional tyrosine N-hydroxylase, cytochrome P450TYR (CYP79), from Sorghum bicolor catalyzing the conversion of tyrosine to p-hydroxyphenyl-acetaldoxime in the biosynthesis of the cyanogenic glucoside dhurrin, has been expressed in Escherichia coli using the isopropyl-beta-D-thiogalactopyranoside-inducible vector pSP19g10L, containing the cDNA encoding CYP79. The expression construct was optimized by reducing the length of the N-terminal hydrophobic core of the signal sequence of cytochrome P450TYR and by exchanging the first eight codons with the first eight codons of bovine P45017 alpha. The highest yielding construct provided 200-500 nmol P450TYR/liter cell culture. The recombinant P450TYR was gently and efficiently extracted from E. coli spheroblasts by temperature-induced phase partitioning of Triton X-114 in the presence of 30% glycerol and isolated by DEAE and reactive red chromatography. In reconstitution experiments using saturating amounts of sorghum NADPH-cytochrome P450 reductase, the Km and turnover rate for isolated recombinant P450TYR was 0.22 +/- 0.06 mM and 49.2 +/- 3.8 min-1, respectively, whereas a turnover rate as high as 350 min-1, was obtained using E. coli membranes. Addition of 3 mM glutathione stimulated the activity of reconstituted P450TYR and of sorghum microsomes although the effect was highly variable. Phenylalanine, the precursor of several cyanogenic glucosides, gave a type I binding spectrum, but was not metabolized by P450TYR, demonstrating the high substrate specificity of this P450. Administration of radioactively labeled p-hydroxyphenylacetaldoxime to E. coli cells, showed E. coli metabolized p-hydroxyphenylacetaldoxime independent of the expression of P450TYR.
journal_name
Arch Biochem Biophysjournal_title
Archives of biochemistry and biophysicsauthors
Halkier BA,Nielsen HL,Koch B,Møller BLdoi
10.1006/abbi.1995.1477subject
Has Abstractpub_date
1995-10-01 00:00:00pages
369-77issue
2eissn
0003-9861issn
1096-0384pii
S0003-9861(85)71477-4journal_volume
322pub_type
杂志文章abstract：:DLIF (digoxin-like immunoreactive factor) and OLF (ouabain-like factor) are endogenous steroid-like ligands (approximately 781 and 595 Da, respectively) with molecular and structural properties similar to the plant-derived cardiac glycosides, digoxin and ouabain. We developed a purification method with a sufficiently ...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1996.0160
更新日期：1996-04-01 00:00:00
abstract：:The sesquiterpene cyclase, aristolochene synthase, has been purified from Penicillium roqueforti by gel filtration and anion-exchange chromatography. Isolation was facilitated by a change in the elution behavior of the enzyme during gel filtration at different steps in the purification. The purified enzyme had a speci...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(89)90204-x
更新日期：1989-07-01 00:00:00
abstract：:Recombinant glutathione S-transferase P (GST-P) was purified in a homogeneous state. Fatty acid analysis of the enzyme revealed that the final enzyme preparation endogenously bound fatty acids, mostly palmitic acid or stearic acid, which were difficult to dissociate from the complex. Temperature-dependent analysis by ...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1993.1190
更新日期：1993-04-01 00:00:00
abstract：:Sequence analyses of the C-terminal membrane intercalative region of the rat cytochrome b(5) indicated that this domain has, in addition to a signal sequence, a combined element of the classic stop-transfer sequence typically found in a variety of transmembrane proteins. Such bitopic protein arrangements arise by tand...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/s0003-9861(03)00051-1
更新日期：2003-04-15 00:00:00
abstract：:Xanthine dehydrogenase was purified from soybean nodules and the kinetic properties were studied at pH 7.5. Km values of 5.0 +/- 0.6 and 12.5 +/- 2.5 microM were obtained for xanthine and NAD+, respectively. The pattern of substrate dependence suggested a Ping-Pong mechanism. Reaction with hypoxanthine gave Km's of 52...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(83)90542-8
更新日期：1983-04-15 00:00:00
abstract：:The human folate receptor (hFR) is a plasma membrane protein that is anchored to the membrane via a glycosylphosphatidylinositol (GPI) tail in some cell types. The KB hFR cDNA sequence predicts a hydrophobic, alpha-helical 31-residue carboxyl terminus that is thought to be the signal for cleavage and attachment of the...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1995.1456
更新日期：1995-09-10 00:00:00
abstract：:D-Proline is converted to 5-amino valeric acid by D-proline reductase. This conversion involves the reductive cleavage of the alpha-carbon-nitrogen bond. We have examined the fate of the carboxyl oxygen atoms during conversion of D-proline to delta-NH2-valeric acid. 18O atoms from the carboxyl group of D-proline are n...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1994.1262
更新日期：1994-06-01 00:00:00
abstract：:To assess the effect of a polymeric surfactant, Pluronic P-105 on the activity of electron transport chains in the mitochondria of HL-60 cells, the bioreduction rates of two membrane-localized lipophilic spin probes, 16-doxylstearic acid methyl ester (16-DSME) and 5-doxylstearic acid (5-DS), were studied. In addition,...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.2000.2104
更新日期：2000-12-01 00:00:00
abstract：:Phosphatidylinositol (PtdIns) and many other phospholipids activated calmodulin (CaM)-dependent phosphatase in the presence or absence of Ca2+, and the stimulation was more pronounced in the presence of Ca2+. In addition, PtdIns modulated the response of phosphatase to CaM: at low and nonstimulatory concentrations (le...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(89)90005-2
更新日期：1989-04-01 00:00:00
abstract：:The influences of selenium deficiency (Se-D), chronic training, and an acute bout of exercise on hepatic and skeletal muscle antioxidant enzymes, i.e., superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPX), as well as glutathione S-transferase (GST) and tissue lipid peroxidation, were investigated in ...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(88)90623-6
更新日期：1988-05-15 00:00:00
abstract：:Cholesterol is an important lipid molecule and is needed for all mammalian cells. In various cell types, excess cholesterol is stored as cholesteryl esters; acyl-CoA:cholesterol acyltransferase 1 (ACAT1) plays an essential role in this storage process. ACAT1 is located at the endoplasmic reticulum and has nine transme...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2019.06.006
更新日期：2019-08-15 00:00:00
abstract：:During the deglycosylation reaction of fish egg polysialoglycoproteins under the conditions of 1 M NaBH4 in 0.1 M NaOH at 37 degrees C for 48 h, a marked loss of the glycine content has been encountered, besides the serine and threonine residues to which the carbohydrate units are linked. The chemical basis behind thi...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(84)90590-3
更新日期：1984-08-01 00:00:00
abstract：:Organic hydroperoxides can replace NADPH in supporting the oxidation of ethanol by liver microsomes. Experiments were carried out to evaluate the role of hydroxyl radicals in the organic hydroperoxide-catalyzed reaction. Maximum rates of ethanol oxidation occurred in the presence of either 0.5 mM cumene hydroperoxide ...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(83)90377-6
更新日期：1983-11-01 00:00:00
abstract：:Pokeweed (Phytolacca americana) antiviral protein (PAP) is a glycosidase which inactivates both eukaryotic and prokaryotic ribosomes. Due to this activity the wild-type PAP gene encoding mature protein has not so far been expressed in Escherichia coli. In spite of the ribosome impairing activity of the pre-PAP (contai...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1997.0552
更新日期：1998-03-01 00:00:00
abstract：:CYP3A9 is an estrogen-inducible ortholog of human liver CYP3A4 with 76.5% sequence identity to CYP3A4. Unlike CYP3A4, it is a very poor testosterone 6beta- and 2beta-hydroxylase, but a relatively better catalyst of progesterone monohydroxylation largely at 6beta, 16alpha, and 21 positions with negligible 6beta, 21-dih...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/s0003-9861(02)00582-9
更新日期：2003-01-01 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：:2-Chlorodeoxyadenosine (CldAdo, Cladribine), a nucleoside analog used in the treatment of hairy cell leukemia, is phosphorylated and incorporated into DNA, but is not an absolute chain terminator. We hypothesized that the presence of a chlorine molecule projecting into the DNA minor groove would affect DNA:protein-bin...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2006.12.031
更新日期：2007-03-15 00:00:00
abstract：:Glutathione S-transferases (GSTs) of Plasmodium parasites are potential targets for antimalarial drug and vaccine development. We investigated the equilibrium unfolding, functional activity regulation and stability characteristics of the unique GST of Plasmodium vivax (PvGST). Despite high sequence, structural, functi...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2009.05.011
更新日期：2009-07-15 00:00:00
abstract：:Glycerol phosphate acyltransferase (GPAT) catalyzes the formation of 1-acyl-sn-glycerol-3-phosphate from glycerol-3-phosphate and long chain fatty acyl-CoA substrates. We previously determined the topography of the mitochondrial GPAT1 isoform (mtGPAT1, 828 amino acids). mtGPAT1 has two transmembrane domains (TMDs) (aa...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2006.03.009
更新日期：2006-06-15 00:00:00
abstract：:A new enzyme homologous to phosphotriesterase was identified from the bacterium Geobacillus stearothermophilus (GsP). This enzyme belongs to the amidohydrolase family and possesses the ability to hydrolyze both lactone and organophosphate (OP) compounds, making it a phosphotriesterase-like lactonase (PLL). GsP possess...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2009.06.005
更新日期：2009-08-15 00:00:00
abstract：:A radioimmunoassay was developed to assess the response of testicular HO-1 to agents known to increase the microsomal heme oxygenase activity. Treatment of rats with human chorionic gonadotropin (hCG) increased the microsomal heme oxygenase activity in rat testis. The following data suggest that the increase was speci...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(89)90569-9
更新日期：1989-01-01 00:00:00
abstract：:Saccharomyces cerevisiae sterol and heme auxotrophs were used to elucidate a role for hemes in sterol esterification. Steryl ester synthase (SES) activity was stimulated on average fourfold in cells supplemented with 50 micrograms/ml delta-aminolevulinic acid (ALA). This stimulation was not dependent on ALA per se, bu...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(92)90600-2
更新日期：1992-08-01 00:00:00
abstract：:PFam Clan 0032, also known as the CDE superfamily, is a diverse group of at least 20 protein families sharing a common α,β-barrel domain. Of these, six different groups bind heme inside the barrel's interior, using it alternately as a cofactor, substrate, or product. Focusing on these six, an integrated picture of str...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章,评审
doi：10.1016/j.abb.2015.03.004
更新日期：2015-05-15 00:00:00
abstract：:Kinetic analysis has shown that dimethylnitrosamine, dipropylnitrosamine, dibutylnitrosamine, and diphenylnitrosamine initially act as reversible competitive inhibitors with respect to the substrate, acetylthiocholine chloride. The inhibitor constants Ki vary from 21-30 microM for the aliphatic nitrosamines to 8.2 mic...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(90)90500-x
更新日期：1990-06-01 00:00:00
abstract：:Triosephosphate isomerase from rabbit has 5 Cys and 2 Met, while triosephosphate isomerase from yeast has 2 Cys (present in the rabbit enzyme in equivalent positions) and no Met. Since chloramine-T oxidizes Cys and Met, we determined the effect it has on the activity and structure of both enzymes. The activity of trio...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1994.1395
更新日期：1994-09-01 00:00:00
abstract：:The majority of hypertrophic cardiomyopathy mutations in (cTnT) occur within the alpha-helical tropomyosin binding TNT1 domain. A highly charged region at the C-terminal end of TNT1 unwinds to create a flexible "hinge". While this region has not been structurally resolved, it likely acts as an extended linker between ...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2014.01.016
更新日期：2014-06-15 00:00:00
abstract：:The dioxathiadiaza-heteropentalenes, HEP-I (4,4-dimethyl-1,7-dioxa-2,6-diaza- 7 alpha lambda 4-thia-3H,5H-benzo[cd]pentalene), HEP-II (1,7-dioxa-2, 6-diaza-4, 7 alpha lambda 4-dithia-3H, 5H-benzo[cd]pentalene), HEP-III (1,7-dioxa-2,6-diaza-4, 7 alpha lambda 4-dithia-3H, 5H-benzo[cd]pentalene-4-oxide), and HEP-IV (1,7-...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(89)90574-2
更新日期：1989-01-01 00:00:00
abstract：:The cross-reactivity of the monoclonal anti-human placental DNA methyltransferase antibody M2B10 with DNA methyltransferases isolated from other species was investigated. This antibody immunoprecipitates DNA methyltransferases from mammalian cells, i.e., human placenta, mouse P815 cells, and rat liver cells. No cross-...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(89)90599-7
更新日期：1989-01-01 00:00:00
abstract：:Dethiolation of proteins (reduction of protein mixed disulfides) by NADPH-dependent and glutathione (GSH)-dependent enzymes, and by nonenzymatic reaction with GSH, was studied by electrofocusing methodology with glycogen phosphorylase b and creatine kinase as substrates. Phosphorylase b was not rapidly dethiolated by ...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(89)90413-x
更新日期：1989-10-01 00:00:00
abstract：:Cystalysin, the key virulence factor in the bacterium Treponema denticola responsible for periodontis, is a pyridoxal 5'-phosphate (PLP) enzyme which catalyzes, in addition to alpha,beta-elimination of L-cysteine, racemization and transamination of both enantiomers of alanine. In this paper several indicators have bee...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2006.08.020
更新日期：2006-11-01 00:00:00
