Abstract：
:One cause of multidrug resistance is the overexpression of P-glycoprotein, a 170 kDa plasma membrane ABC transporter, which functions as an ATP-driven efflux pump with broad specificity for hydrophobic drugs, peptides, and natural products. The protein appears to interact with its substrates within the membrane environment. Previous reports suggested the existence of at least two binding sites, possibly overlapping and displaying positively cooperative interactions, termed the H and R sites for their preference for Hoechst 33342 and rhodamine 123, respectively. In this work, we have used several fluorescence approaches to characterize the molecular interaction of purified P-glycoprotein (Pgp) with the dye LDS-751, which is proposed to bind to the R site. A 50-fold enhancement of LDS-751 fluorescence indicated that the protein binding site was located in a hydrophobic environment, with a polarity lower than that of chloroform. LDS-751 bound with sub-micromolar affinity (K(d) = 0.75 microM) and quenched P-glycoprotein intrinsic Trp fluorescence by 40%, suggesting that Trp emitters are probably located close to the drub-binding regions of the transporter and may interact directly with the dye. Using a FRET approach, we mapped the possible locations of the LDS-751 binding site relative to the NB domain active sites. The R site appeared to be positioned close to the membrane boundary of the cytoplasmic leaflet. The location of both H and R drug binding sites is in agreement with the idea that Pgp may operate as a drug flippase, moving substrates from the inner leaflet to the outer leaflet of the plasma membrane.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Lugo MR,Sharom FJdoi
10.1021/bi0485326subject
Has Abstractpub_date
2005-01-18 00:00:00pages
643-55issue
2eissn
0006-2960issn
1520-4995journal_volume
44pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract：:Large primary deuterium kinetic isotope effects (1° DKIEs) on enzyme-catalyzed hydride transfer may be observed when the transferred hydride tunnels through the energy barrier. The following 1° DKIEs on kcat/ Km and relative reaction driving force are reported for wild-type and mutant glycerol-3-phosphate dehydrogenas...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/acs.biochem.8b00536
更新日期：2018-07-24 00:00:00
abstract：:Fibronectin (FN) is an extracellular matrix (ECM) protein found soluble in corporal fluids or as an insoluble fibrillar component incorporated in the ECM. This phenomenon implicates structural changes that expose FN binding sites and activate the protein to promote intermolecular interactions with other FN. We have in...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi0347104
更新日期：2004-02-17 00:00:00
abstract：:Reducing sugars such as glucose react nonenzymatically with protein amino groups to initiate a posttranslational modification process known as advanced glycosylation. Nucleotide bases also participate in advanced glycosylation reactions, producing DNA-linked advanced glycosylation endproducts (AGEs) that cause mutatio...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00002a032
更新日期：1995-01-17 00:00:00
abstract：:Eukaryotic assimilatory nitrate reductase (NR) is a dimeric multidomain molybdo-heme-flavo protein that catalyzes the first and rate-limiting step in the nitrate assimilation of plants, algae, and fungi. Nitrate reduction takes place at the N-terminal molybdenum cofactor-containing domain. Reducing equivalents are der...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi1003487
更新日期：2010-09-21 00:00:00
abstract：:The inheritance of DNA methylation patterns may play an important role in the stability of the differentiated state. We have therefore studied the inhibitory effects of DNA binding proteins on DNA methylation in vitro. Mouse L1210 cells grown in the presence of 5-azacytidine acquire hemimethylated sites in their DNA. ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00326a021
更新日期：1985-02-26 00:00:00
abstract：:The targeting of the insulin-responsive glucose transporter, GLUT-4, to an intracellular compartment in adipocytes and muscle is one of the key features responsible for the unique insulin sensitivity of this transporter. Through expression of epitope-tagged GLUT-4 mutants in 3T3-L1 adipocytes, two motifs have been ide...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi980988y
更新日期：1999-02-02 00:00:00
abstract：:Molecular dynamics simulations employing a molecular mechanics (MM) force field and hybrid quantum mechanics (QM) and MM (QM/MM) have been carried out to investigate the product specificity and mechanism of the histone H4 lysine 20 (H4-K20) methylation by human histone lysine methyltransferase SET8. At neutral pH, the...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi800244s
更新日期：2008-06-24 00:00:00
abstract：:Treatment of the beta 2 adrenergic receptor with the reducing agent dithiothreitol (DTT) is known to abolish ligand binding to the receptor. Interestingly, the loss of binding can be prevented by preoccupation of the receptor with ligand. It is unclear, however, whether the ligand blocks access of DTT to the receptor,...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi961619+
更新日期：1996-11-19 00:00:00
abstract：:The temperature dependence of the hydrogen-tritium and deuterium-hydrogen exchange reactions in poly(DL-alanine) has been reexamined. The results indicate a significant contribution to the observed exchange rates from the water-catalyzed reaction at pD values near pDmin. The activation enthalpy for water-catalyzed deu...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00273a031
更新日期：1983-02-15 00:00:00
abstract：:We have previously shown that introduction of an engineered Met160 residue in ascorbate peroxidase (S160M variant) leads to the formation of a covalent link between Met160 and the heme vinyl group [Metcalfe, C. L., et al. (2004) J. Am. Chem. Soc. 126, 16242-16248]. In this work, we have used electronic spectroscopy, H...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi7015316
更新日期：2007-11-20 00:00:00
abstract：:The first use of computer-simulation studies to examine heparin's structure has been reported. The product distributions obtained when porcine mucosal heparins were depolymerized with heparinase have been compared to computer-simulated distributions. The modeled distribution was relatively unaffected by the polydisper...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00347a045
更新日期：1985-12-17 00:00:00
abstract：:The transcriptional activity of the beta-globin genes is regulated by a complex genetic element, the locus control region (LCR), at the 5'-end of the beta-globin locus. Tandem binding sites for the erythroid-specific transcription factor NF-E2 are important for the transcriptional activation function of the LCR. We di...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00050a015
更新日期：1995-12-19 00:00:00
abstract：:G-protein-coupled receptors (GPCRs) represent the largest class of drug targets, accounting for more than 40% of marketed drugs; however, discovery efforts for many GPCRs have failed to provide viable drug candidates. Historically, drug discovery efforts have focused on developing ligands that act at the orthosteric s...
journal_title：Biochemistry
pub_type： 杂志文章,评审
doi：10.1021/bi200129s
更新日期：2011-04-05 00:00:00
abstract：:The differential scanning calorimetry trace of F1ATPase, prepared from beef heart submitochondrial particles, has a single sharp endothermic transition at 80.5 +/- 1.0 degrees C and a half-height peak width of 2.0 +/- 0.2 degrees. The transition enthalpy is 19 +/- 2 cal/g of protein. Submitochondrial particles (SMP) h...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00328a022
更新日期：1985-03-26 00:00:00
abstract：:Desosamine is a 3-(dimethylamino)-3,4,6-trideoxyhexose found, for example, in such macrolide antibiotics as erthyromycin, azithromycin, and clarithromycin. The efficacies of these macrolide antibiotics are markedly reduced in the absence of desosamine. In the bacterium Streptomyces venezuelae, six enzymes are required...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi700751d
更新日期：2007-08-07 00:00:00
abstract：:Steady-state kinetic parameters were determined for the human leukocyte elastase catalyzed hydrolysis of a series of peptide-based thiobenzyl esters and p-nitroanilides. The peptide units are MeOSuc-Val, MeOSuc-Alan-Pro-Val (n = 0-2), and MeOSuc-Alan-Pro-Ala (n = 1 or 2). The results of this study suggest five importa...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00379a015
更新日期：1987-03-10 00:00:00
abstract：:The mechanisms of interaction of the recombinant N-terminal portion of bactericidal/permeability-increasing protein, rBPI21, with various planar asymmetric and symmetric bilayer membranes, including the lipid matrix of the outer membrane of Gram-negative bacteria, were investigated via electrical measurements. For the...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi970177e
更新日期：1997-08-19 00:00:00
abstract：:Phosphorescence from the lone tryptophan residue has been studied to monitor the interaction of myelin basic protein with phosphatidylserine vesicles. Spectral shifts in the phosphorescence of the protein in a glycerol-buffer (70:30 w/w) solvent at low temperature are consistent with fluorescence data obtained under a...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00514a019
更新日期：1981-05-26 00:00:00
abstract：:The allosteric activation of the T127-->L mutant of 3',5'-cyclic adenosine monophosphate (cAMP) receptor protein (CRP) by cAMP changes from an exothermic, independent two-site binding mechanism at pH 7.0 to an endothermic, interacting two-site binding mechanism at pH 5.2, similar to that observed for CRP at pH 7.0 and...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi000225m
更新日期：2000-06-20 00:00:00
abstract：:Z-disc-associated, alternatively spliced, PDZ motif-containing protein (ZASP) is a principal component of the sarcomere. The three prevalent isoforms of ZASP in skeletal muscle are generated by alternative splicing of exons 9 and 10. The long isoforms, either having (ZASP-L) or lacking exon 10 (ZASP-LΔex10), include a...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/acs.biochem.7b00067
更新日期：2017-04-11 00:00:00
abstract：:PsbO, the photosystem II manganese stabilizing protein, contains an aspartate residue [Asp157 (spinach numbering)], which is highly conserved in eukaryotic and prokaryotic PsbOs. The homology model of the PSII-bound conformation of spinach PsbO presented here positions Asp157 in the large flexible loop of the protein....
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi9016999
更新日期：2009-12-22 00:00:00
abstract：:A dipeptide containing the binding site for retinal in bovine rhodopsin has been isolated and its sequence determined. Rhodopsin containing [11-3H]retinal was prepared in chromatographically pure form, and the [3H]retinal was reductively linked to its binding site on opsin by using borane--dimethylamine. The [3H]retin...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00563a027
更新日期：1980-10-28 00:00:00
abstract：:We have investigated the effects of mixed Na+: Mg2+ ionic solutions on the stability of the nonspecific lac repressor-DNA complex. The effects of Mg2+ are simply interpreted in terms of its role as a competitor (with repressor) for DNA sites. From these studies, the binding constant of the Mg-DNA complex can be determ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00641a005
更新日期：1977-11-01 00:00:00
abstract：:Previous studies have demonstrated that lung-specific proteins are associated with surfactant lipids, particularly the highly surface active subfraction known as tubular myelin. We have isolated a surfactant-associated protein complex with molecular weight components of 36 000, 32 000, and 28 000 and reassembled it wi...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00322a026
更新日期：1985-01-01 00:00:00
abstract：:The binding of agonists, antagonists, and the acetylcholinesterase inhibitor, eserine, to the nicotinic acetylcholine receptor from Torpedo californica has been monitored by the fluorescence changes of two extrinsic probes that have been covalently attached to the receptor protein. Although both probes, 5-(iodoacetami...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00084a031
更新日期：1993-08-24 00:00:00
abstract：:The interaction of bovine spleen profilin with ATP- and ADP-G-actin and poly(L-proline) has been studied by spectrofluorimetry, analytical ultracentrifugation, and rapid kinetics in low ionic strength buffer. Profilin binding to G-actin is accompanied by a large quenching of tryptophan fluorescence, allowing the measu...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00194a011
更新日期：1994-07-19 00:00:00
abstract：:Self-splicing of Tetrahymena pre-rRNA proceeds in two consecutive phosphoryl transesterification steps. One major difference between these steps is that in the first an exogenous guanosine (G) binds to the active site, while in the second the 3'-terminal G414 residue of the intron binds. The first step has been extens...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi9527653
更新日期：1996-05-07 00:00:00
abstract：:Ran, a small nuclear GTP-binding protein, is one of the most abundant Ras-related proteins in eucaryotic cells. Ran is essential for nucleo-cytoplasmatic transport and is primarily localized in the nucleus and at the nuclear pore complex. Here, we characterize the kinetics and equilibrium of the interaction between Ra...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi970524k
更新日期：1997-10-07 00:00:00
abstract：:The immunoglobulin E-binding protein, epsilon BP (also known as CBP35, Mac-2, L-34, and L-29), is a beta-galactoside-binding protein of approximately 30 kDa and a member of the animal lectin family termed S-type or S-Lac. Multiple biological activities have been attributed to this lectin such as mediation of IgE bindi...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00186a038
更新日期：1994-05-24 00:00:00
abstract：:Kinetics studies of dNTP analogues having pyrophosphate-mimicking β,γ-pCXYp leaving groups with variable X and Y substitution reveal striking differences in the chemical transition-state energy for DNA polymerase β that depend on all aspects of base-pairing configurations, including whether the incoming dNTP is a puri...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi500101z
更新日期：2014-03-25 00:00:00
