Abstract:
:The direct transfer of NADH between A-B pairs of dehydrogenases and also the dissociation of NADH from individual E-NADH complexes have been investigated by transient stopped-flow kinetic techniques. Such A-B transfers of NADH occur without the intermediate dissociation of coenzyme into the aqueous solvent environment [Srivastava, D.K., & Bernhard, S.A. (1985) Biochemistry 24, 623-628]. The equilibrium distributions of limiting NADH among aqueous solvent and A and B dehydrogenase sites have also been determined. At sufficiently high but realizable concentrations of dehydrogenases, both the transfer rate and the equilibrium distribution of bound NADH are virtually independent of the excessive enzyme concentrations; at excessive E2 concentration, substantial NADH is bound to the E1 site. These results further substantiate earlier kinetic arguments for the preferential formation of an EA-NADH-EB complex, within which coenzyme is directly transferred between sites. The unimolecular specific rates of coenzyme transfer from site to site are nearly invariant among different A-B dehydrogenase pairs. The equilibrium constants for the distribution of coenzyme within the EA X EB complexes are near unity. At high [E2] and for [E2] greater than [E1] greater than [NADH], E1-NADH X E2 and E1 X NADH-E2 are virtually the only coenzyme-contained species. In contrast to the nearly invariant unimolecular NADH transfer rates within EA X EB complexes, unimolecular specific rates of dissociation of NADH from E-NADH into aqueous solution are highly variable.(ABSTRACT TRUNCATED AT 250 WORDS)
journal_name
Biochemistryjournal_title
Biochemistryauthors
Srivastava DK,Bernhard SAdoi
10.1021/bi00379a006subject
Has Abstractpub_date
1987-03-10 00:00:00pages
1240-6issue
5eissn
0006-2960issn
1520-4995journal_volume
26pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::Proteolytic activation, oligomerization, and membrane insertion are three steps that precede channel formation by the bacterial toxin aerolysin. Using attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and hydrogen-deuterium exchange, the structural changes associated with each step were an...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi971216p
更新日期:1997-12-09 00:00:00
abstract::Carbohydrate-binding module (CBM) family 13 includes the "R-type" or "ricin superfamily" beta-trefoil lectins. The C-terminal CBM, CBM13, of xylanase 10A from Streptomyces lividans is a family 13 CBM that is not only structurally similar to the "R-type" lectins but also somewhat functionally similar. The primary funct...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi015865j
更新日期:2002-04-02 00:00:00
abstract::We have biochemically and kinetically characterized the polymerase and exonuclease activities of the third B-family polymerase (Dpo3) from the hyperthermophilic Crenarchaeon, Sulfolobus solfataricus (Sso). We have established through mutagenesis that despite incomplete sequence conservation, the polymerase and exonucl...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi201799a
更新日期:2012-03-06 00:00:00
abstract::The organization principles underlying non-membrane-bound organelles have started to unravel in the past 10 years. A new biophysical model known as biomolecular condensates has been proposed to explain many aspects of membraneless organelle assembly and regulation. Neurons are extremely complex, and each neuron can co...
journal_title:Biochemistry
pub_type: 杂志文章,评审
doi:10.1021/acs.biochem.8b00313
更新日期:2018-05-01 00:00:00
abstract::Purified beta subunit of human chorionic gonadotropin (hCG) was partially reduced with beta-mercaptoethanol, carboxymethylated, and digested with chymotrypsin. The peptides were isolated by high-voltage electrophoresis and paper chromatography. Five major disulfide-containing peptides were isolated, and their location...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00619a034
更新日期:1978-12-26 00:00:00
abstract::The sterol (free and esterified cholesterol) transport activity of the small-intestinal brush border membrane was solubilized with the short-chain detergent diheptanoylphosphatidylcholine and reconstituted to an artificial membrane system (proteoliposomes). The resulting proteoliposomes were identified as unilamellar ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi970625i
更新日期:1997-09-02 00:00:00
abstract::The hydration of CO2 catalyzed by carbonic anhydrase requires proton transfer from the zinc-bound water at the active site to solution for each cycle of catalysis. In the most efficient of the mammalian carbonic anhydrases, isozyme II, this transfer is facilitated by a proton shuttle residue, His 64. Murine carbonic a...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9729209
更新日期:1998-05-19 00:00:00
abstract::The integral membrane protein diacylglycerol kinase (DGK) from Escherichia coli has been reversibly unfolded in a protein/detergent/mixed micelle system by varying the molar ratio of n-decyl beta-D-maltoside (DM) and sodium dodecyl sulfate (SDS). Unfolding was monitored by circular dichroism (CD) and ultraviolet (UV) ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi963095j
更新日期:1997-05-13 00:00:00
abstract::Acyl carrier protein (ACP) is a cofactor in a variety of biosynthetic pathways, including fatty acid metabolism. Thus, it is of interest to determine structures of physiologically relevant ACP-fatty acid complexes. We report here the NMR solution structures of spinach ACP with decanoate (10:0-ACP) and stearate (18:0-A...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi052062d
更新日期:2006-04-25 00:00:00
abstract::Factor IX activation by factor XIa is thought to proceed through the singly-cleaved free intermediate, factor IX alpha. However, we observed no intermediate development during factor IX activation by factor XIa when using a low substrate to enzyme ratio (44:1 mol/mol). This result can be explained by one of two mechan...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi962274y
更新日期:1997-04-08 00:00:00
abstract::Two high molecular weight DNA polymerases, which we have designated delta I and delta II, have been purified from calf thymus tissue. Using Bio Rex-70, DEAE-Sephadex A-25, and DNA affinity resin chromatography followed by sucrose gradient sedimentation, we purified DNA polymerase delta I 1400-fold to a specific activi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00349a005
更新日期:1986-01-14 00:00:00
abstract::Base excision repair (BER) plays a vital role in maintaining genomic integrity in mammalian cells. DNA polymerase λ (Pol λ) is believed to play a backup role to DNA polymerase β (Pol β) in base excision repair. Two oxidized abasic lesions that are produced by a variety of DNA-damaging agents, including several antitum...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi301592x
更新日期:2013-02-05 00:00:00
abstract::Oligonucleotides labeled with hexachlorofluorescein (hex) have enabled the interaction of the restriction endonuclease EcoRV with DNA to be evaluated using fluorescence anisotropy. The sensitivity of hex allowed measurements at oligonucleotide concentrations as low as 1 nM, enabling K(D) values in the low nanomolar ra...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi001956p
更新日期:2001-02-27 00:00:00
abstract::We have assayed the cross-linking of oligonucleotides containing repeated mitomycin-reactive CpG sites in order to assess the factors that enhance activation of the carbamoyl function at C10, yielding efficient mitomycin cross-linking. Drugs studied include mitomycin C (MC), N-methylmitomycin A (NMA), and the aziridin...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00439a049
更新日期:1989-06-27 00:00:00
abstract::One of the most intriguing questions confronting the bone morphogenetic protein family is the mechanism of ligand recognition, because there are more ligands than receptors. Crystal structures of two type II receptors, ActR-II and BMPR-II, are essentially identical, and a loop structure (A-loop) has been suggested to ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi3003023
更新日期:2012-09-04 00:00:00
abstract::The cytochrome bc(1) complex from Paracoccus denitrificans and soluble fragments of its cytochrome c(1) and Rieske ISP subunits are characterized by a combined approach of protein electrochemistry and FTIR difference spectroscopy. The FTIR difference spectra provide information about alterations in the protein upon re...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi035103j
更新日期:2003-10-28 00:00:00
abstract::In bacteria, regulatory phosphorylation of proteins at serine and/or threonine residues by Ser/Thr protein kinase (STPK) is an emerging theme in prokaryotic signaling, particularly since the prediction of the occurrence of several STPKs from genome sequencing and sequence surveys. Here we show that protein PknH posses...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi035150b
更新日期:2003-12-30 00:00:00
abstract::Ketopantoate reductase (EC 1.1.1.169) catalyzes the NADPH-dependent reduction of alpha-ketopantoate to form D-(-)-pantoate in the pantothenate/coenzyme A biosynthetic pathway. The enzyme encoded by the panE gene from E. coli K12 was overexpressed and purified to homogeneity. The native enzyme exists in solution as a m...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi992676g
更新日期:2000-04-04 00:00:00
abstract::Tandem DNA lesions containing two contiguously damaged nucleotides are commonly formed by ionizing radiation. Their effects on replication in mammalian cells are largely unknown. Replication of isolated 2-deoxyribonolactone (L), thymine glycol (Tg), and tandem lesion 5'-LTg was examined in human cells. Although nearly...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.9b01058
更新日期:2020-02-04 00:00:00
abstract::2-[(R)-2-Hydroxypropylthio]ethanesulfonate (R-HPC) dehydrogenase (DH) catalyzes the reversible oxidation of R-HPC to 2-(2-ketopropylthio)ethanesulfonate (2-KPC) in a key reaction in the bacterial conversion of chiral epoxides to beta-keto acids. R-HPCDH is highly specific for the R-enantiomer of HPC, while a separate ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi049783h
更新日期:2004-06-01 00:00:00
abstract::Directed hydroxyl radical probing of 16S ribosomal RNA from Fe(II) tethered to specific sites within the RNA was used to determine RNA-RNA proximities in 70S ribosomes. We have transcribed 16S ribosomal RNA in vitro as two separate fragments, covalently attached an Fe(II) probe to a 5'-guanosine-alpha-phosphorothioate...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi981644a
更新日期:1999-01-19 00:00:00
abstract::Serine hydroxymethyltransferase (SHMT) catalyzes the reversible conversion of l-serine and tetrahydrofolate into glycine and 5,10-methylenetetrahydrofolate. This enzyme, which plays a pivotal role in one-carbon metabolism, is involved in cancer metabolic reprogramming and is a recognized target of chemotherapy interve...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.8b01074
更新日期:2018-12-26 00:00:00
abstract::Escherichia coli asparagine synthetase B (AS-B) catalyzes the synthesis of asparagine from aspartate, glutamine, and ATP. A combination of kinetic, isotopic-labeling, and stoichiometry studies have been performed to define the nature of nitrogen transfer mediated by AS-B. The results of initial rate studies were consi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi981058h
更新日期:1998-09-22 00:00:00
abstract::The X-ray structures of neuronal nitric oxide synthase (nNOS) with N(omega)-hydroxy-l-arginine (l-NHA) and CO (or NO) bound have been determined at 1.91-2.2 A resolution. Microspectrophotometric techniques confirmed reduced redox state and the status of diatomic ligand complexes during X-ray diffraction data collectio...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9009743
更新日期:2009-11-03 00:00:00
abstract::Cryptophycin-52 (LY355703) is currently undergoing clinical evaluation for cancer chemotherapy. It is a potent suppressor of microtubule dynamics in vitro, and low picomolar concentrations appear to inhibit cancer cell proliferation at mitosis by stabilizing spindle microtubules. In the present study, using [(3)H]cryp...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0010827
更新日期:2000-11-21 00:00:00
abstract::Cell-signaling peptides have been extensively used to transport functional molecules across the plasma membrane into living cells. These peptides consist of a hydrophobic sequence and a cationic nuclear localization sequence (NLS). It has been assumed that the hydrophobic region penetrates the hydrophobic lipid bilaye...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi061895g
更新日期:2007-01-30 00:00:00
abstract::The labeling of chloroplast coupling factor 1 by 3'-O-(4-benzoyl)benzoyl-ATP (BzATP) was studied. When the enzyme was incubated with approximately 10 microM BzATP and 6 mM MgCl2 at pH 7.9 for approximately 20 min and passed through two Sephadex G-50 centrifuge columns, three BzATP molecules were bound per coupling fac...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00385a038
更新日期:1987-06-02 00:00:00
abstract::The two-finger repeat in the human male-associated protein ZFY provides a model for comparative 2D-NMR studies of classical and variant Zn fingers. This repeat is defined in part by an alternation in spacing between consensus (HX3H) and variant (HX4H) histidine spacings. To investigate the effects of a "switch" betwee...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00103a002
更新日期:1991-10-01 00:00:00
abstract::Manganese superoxide dismutase (MnSOD) cycles between the Mn(II) and Mn(III) states during the catalyzed disproportionation of O(2)(*-), a catalysis that is limited at micromolar levels of superoxide by a peroxide-inhibited complex with the metal. We have investigated the role in catalysis and inhibition of the conser...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi011047f
更新日期:2001-10-09 00:00:00
abstract::The kinetics of Zn(2+) binding by two point-mutated forms of the HIV-1 NCp7 C-terminal zinc finger, each containing tridentate binding motif HCC [Ser49(35-50)NCp7] or CCC [Ala44(35-50)NCp7], has been studied by stopped-flow spectrofluorimetry. Both the formation and dissociation rate constants of the complexes between...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi047349+
更新日期:2005-05-17 00:00:00