Abstract:
:The role of acidic amino acid residues in cation recognition and selectivity by the Na+/dicarboxylate cotransporter, NaDC-1, was investigated by site-directed mutagenesis and expression in Xenopus oocytes. Four of the residues tested, Asp-52, Glu-74, Glu-101, and Glu-332, were found to be unimportant for transport activity. However, substitutions of Asp-373 and Glu-475, conserved residues found in transmembrane domains M8 and M9, respectively, altered transport kinetics. Replacements of Asp-373 with Ala, Glu, Asn, and Gln resulted in changes in sodium affinity and cation selectivity in NaDC-1, indicating that the carbonyl oxygen at this position may play a role in the topological organization of the cation-binding site. In contrast, substitutions of Glu-475 led to dramatic reductions in transport activity and changes in transport kinetics. Substitution with Gln led to a transporter with increased substrate and sodium affinity, while the E475D mutant was inactive. The E475A mutant appeared to have poor sodium binding. Substrate-induced currents in the E475A mutant exhibited a strong voltage dependence, and a reversal of the current was seen at -30 mV. The results suggest that Glu-475 may play a role in cation binding and possibly also in mediating anion channel activity. Remarkably, mutations of both Asp-373 and Glu-475 affected the Km for succinate in NaDC-1, suggesting dual roles for these residues in determining the affinity for substrate and cations. We propose that at least one of the cation-binding sites and the substrate-binding site are close together in the carboxy-terminal portion of NaDC-1, and thus transmembrane domains M8 and M9 are candidate structures for the formation of the translocation pathway.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Griffith DA,Pajor AMdoi
10.1021/bi990076bsubject
Has Abstractpub_date
1999-06-08 00:00:00pages
7524-31issue
23eissn
0006-2960issn
1520-4995pii
bi990076bjournal_volume
38pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::Here, we introduce the concept of the "seleno effect" in the study of oxidoreductases that catalyze thiol/disulfide exchange reactions. In these reactions, selenium can replace sulfur as a nucleophile, electrophile, or leaving group, and the resulting change in rate (the seleno effect) is defined as kS/ kSe. In soluti...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.8b00004
更新日期:2018-03-20 00:00:00
abstract::The empoyment of a novel method of affinity chromatography, which makes use of antibodies that specifically bind DNA/RNA hybrids, has made it possible to enrich for rat rDNA molecules which contain R loops formed with the 18S and 28S rRNAs. An approximately 150-fold enrichment of the ratrRNA coding sequences was obtai...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00580a030
更新日期:1979-06-26 00:00:00
abstract::The pH-dependent behavior of the ferric forms of two soluble truncations of Rhizobium meliloti FixL, FixL (heme and kinase domains, functional), and FixLN (heme domain) are examined by UV-visible, resonance Raman, and electron paramagnetic resonance spectroscopy. Global analysis of UV-visible data indicates that the p...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi981439v
更新日期:1998-09-29 00:00:00
abstract::To characterize the role of water in protein-DNA interactions, we have studied the specificity of the EcoRI restriction endonuclease as a function of osmotic and hydrostatic pressure. The extent of cleavage by the enzyme at noncanonical ("star") sites is shown to depend uniquely upon the osmotic pressure in the reacti...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00179a001
更新日期:1994-04-05 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::Copper-zinc superoxide dismutase (CuZnSOD) acquires its catalytic copper ion through interaction with another polypeptide termed the copper chaperone for SOD. Here, we combine X-ray crystallographic and analytical ultracentrifugation methods to characterize rigorously both truncated and full-length forms of apo-LYS7, ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi992716g
更新日期:2000-04-04 00:00:00
abstract::Two synthetic peptides corresponding to sequences in HIV-1LAI gp41, (aa558-595) and T20 (aa 643-678), are strong inhibitors of HIV-1 viral fusion, having EC50 values of 1 microgram/mL and 1 ng/mL, respectively. Previous work suggested that T21 forms a coiled-coil structure in PBS solution, while T20 is primarily nonhe...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9606962
更新日期:1996-10-22 00:00:00
abstract::We have measured the hydration of CO2 catalyzed by bovine red cell carbonic anhydrase in mixtures of H2O and D2O at pH(D) which is in the plateau region of the pH--activity profile. The steady-state parameters for hydration Vmax and Km both show an exponential dependence on the atom fraction of deuterium in solvent wa...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00563a008
更新日期:1980-10-28 00:00:00
abstract::Bacterial cytochrome P450cam catalyzes the hydroxylation of camphor to yield 5-exo-hydroxycamphor in vivo and in a reconstituted system with oxygen, pyridine nucleotide, flavoprotein dehydrogenase, and putidaredoxin. Product is also formed when the ferric form of the hemoprotein is mixed with the exogenous oxidants io...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00531a026
更新日期:1982-01-19 00:00:00
abstract::The peptide alpha 1(III)-CB9 was prepared and purified from human liver, and its amino acid sequence was determined. Automated Edman degradation of the intact peptide and peptides derived from selective cleavage with hydroxylamine and digestions with trypsin, thermolysin, and Staph V8 protease enabled determination of...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00512a040
更新日期:1981-04-28 00:00:00
abstract::CopA, a thermophilic membrane ATPase from Archaeoglobus fulgidus, drives the outward movement of Cu(+) or Ag(+) [Mandal et al. (2002) J. Biol. Chem. 277, 7201-7208]. This, as other P(IB)-ATPases, is characterized by a putative metal binding sequence (C(380)PC(382)) in its sixth transmembrane fragment and cytoplasmic m...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi034806y
更新日期:2003-09-23 00:00:00
abstract::The pre-steady-state kinetics of the trichodiene synthase reaction were investigated by rapid chemical quench methods. The single-turnover rate was found to be 3.5-3.8 s-1, a rate 40 times faster than the steady-state catalytic rate (kcat = 0.09 s-1) for trichodiene synthase-catalyzed conversion of farnesyl diphosphat...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi963018o
更新日期:1997-07-08 00:00:00
abstract::Mycobacterial Ser/Thr kinase, PknB, is essential for the growth of the pathogen. Unphosphorylated PknB is catalytically inactive, and its activation requires autophosphorylation of Thr residues on the activation loop. Autophosphorylation can in principle take place via two distinct mechanisms. Intermolecular trans aut...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi500245v
更新日期:2014-07-22 00:00:00
abstract::Bacteriophage P22 is a double-stranded DNA containing phage. Its morphogenetic pathway requires the formation of a precursor procapsid that subsequently matures to the capsid. The stability of bacteriophage P22 coat protein in both monomeric and polymeric forms under hydrostatic pressure has been examined previously [...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00004a003
更新日期:1995-01-31 00:00:00
abstract::Traditionally, assigning the heme protein resonances has relied heavily on the comparison of spectra arising from protein reconstituted with specifically deuterated hemes and the native form. Such an approach can identify tentatively the broad, overlapping signals in the Fe(II) high-spin heme protein spectra. Although...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00202a012
更新日期:1994-09-13 00:00:00
abstract::The identity of the sites of insulin-stimulated serine phosphorylation in the human insulin receptor was examined by synthesizing peptides that together encompassed all the serine residues of the cytosolic portion of the beta-subunit and testing them as substrates for phosphorylation by a preparation of human insulin ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00029a025
更新日期:1995-07-25 00:00:00
abstract::The phosphorelay signal transduction pathway controls sporulation initiation in Bacillus subtilis. Transfer of a phosphoryl group from multiple kinases (KinA and KinB) through a single domain response regulator homologue (Spo0F), a phosphotransferase (Spo0B), and ultimately to a transcriptional regulator, (Spo0A) acti...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi981340o
更新日期:1998-11-24 00:00:00
abstract::The E2 protein of papillomavirus is the key regulator of viral transcription and replication. Dimerization, which takes place via its conserved C-terminal DNA-binding domain (DBD), is critical for these functions. The presence and conservation of two histidines (H290 and H320) at or near the dimer interface suggests t...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0611255
更新日期:2007-02-06 00:00:00
abstract::To determine if mutations introduced into phospholemman (PLM) could increase the level of PLM-Na,K-ATPase (NKA) binding, we performed scanning mutagenesis of the transmembrane domain of PLM and measured Förster resonance energy transfer (FRET) between each mutant and NKA. We observed an increased level of binding to N...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.6b00633
更新日期:2016-11-08 00:00:00
abstract::Reactive metabolites of environmental chemicals and drugs can cause site specific damage to the p53 tumor suppressor gene in a major pathway for genotoxicity. We report here a high-throughput, cell-free, 96-well plate magnetic bead-enzyme system interfaced with LC-MS/MS sequencing for bioactivating test chemicals and ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.8b00271
更新日期:2018-07-03 00:00:00
abstract::Myosin subfragment 1 (S1) was covalently labeled with a fluorescent dye, N-[7-(dimethylamino)-4-methyl-3-coumarinyl]maleimide (DACM), and then digested by trypsin to cleave S1 heavy chain into fragments. The DACM-labeled and trypsin-treated S1 was complexed with F-actin and treated with a zero-length cross-linker, 1-e...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00262a043
更新日期:1982-09-14 00:00:00
abstract::Recombination kinetics of CO to protoheme after laser photolysis have been measured vs. temperature and viscosity. A 25-ns laser pulse was focused on the sample to produce an excitation rate of 10(9)/s per heme. This temporarily populates the heme-CO state of dissociated pairs which either separate or recombine on a p...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00358a008
更新日期:1986-05-20 00:00:00
abstract::The binding of ethidium bromide, as monitored by fluorescence enhancement, to chromatin prepared by nuclease digestion has been compared with the binding of the dye to sheared chromatin. The nuclease preparation (native chromatin) is characterized by a high affinity region of the Scatchard plot (r = 0-0.025, K1 = 1 X ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00622a002
更新日期:1977-02-08 00:00:00
abstract::A versatile diatomic physiological messenger, nitric oxide (NO), is biosynthesized by a group of flavo-heme enzymes, the nitric oxide synthases. We have examined the active site of the neuronal isoform by EPR spectroscopy of the ferrous nitric oxide complex. The nitric oxide complex of the substrate-free enzyme exhibi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi970823+
更新日期:1997-09-09 00:00:00
abstract::A crystal structure of human fibrinogen has been determined at approximately 3.3 A resolution. The protein was purified from human blood plasma, first by a cold ethanol precipitation procedure and then by stepwise chromatography on DEAE-cellulose. A product was obtained that was homogeneous on SDS-polyacrylamide gels....
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi802205g
更新日期:2009-05-12 00:00:00
abstract::In mesophiles, triosephosphate isomerase (TIM) is an obligated homodimer. We have previously shown that monomeric folding intermediates are common in the chemical unfolding of TIM, where dissociation provides 75% of the overall conformational stability of the dimer. However, analysis of the crystallographic structure ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi801360k
更新日期:2008-11-04 00:00:00
abstract::Annexin A1 is a multifunctional, calcium-dependent phospholipid binding protein involved in a host of processes including inflammation, regulation of neuroendocrine signaling, apoptosis, and membrane trafficking. Binding of annexin A1 to glycans has been implicated in cell attachment and modulation of annexin A1 funct...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi101121a
更新日期:2011-04-05 00:00:00
abstract::The side chains of the interacting pair Asp237(helix VII)-Lys358(helix XI) or Asp240(helix VII)-Lys319(helix X) in the lactose permease of Escherichia coli were extended by replacement with Glu and/or Arg or by site-specific derivatization of single-Cys replacement mutants. Iodoacetic acid was used to carboxymethylate...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00089a019
更新日期:1993-09-28 00:00:00
abstract::TCDD (dioxin) induces a rapid inflammatory response from 3T3-L1 adipocytes as judged by prominent induction of the mRNA expression of prostaglandin-endperoxide synthase 2 (Cox-2) along with other inflammation markers within 1 h. This action of TCDD is clearly antagonized by cell pretreatment with AACOCF3 (an inhibitor...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi801913w
更新日期:2008-12-30 00:00:00
abstract::Processing bodies (P-bodies) are cytoplasmic ribonucleoprotein (RNP) granules primarily composed of translationally repressed mRNAs and proteins related to mRNA decay, suggesting roles in post-transcriptional regulation. P-bodies are conserved in eukaryotic cells and exhibit properties of liquid droplets. However, the...
journal_title:Biochemistry
pub_type: 杂志文章,评审
doi:10.1021/acs.biochem.7b01162
更新日期:2018-05-01 00:00:00