Báo cáo khoa học: Modulation of P-glycoprotein-mediated multidrug resistance by acceleration of passive drug permeation across the plasma membrane potx

... permeation of drugs across the plasma membrane. Thus, reversal of multidrug resistance (MDR) can occureither by inhibition of the efflux pumps or by acceleration of the drug per-meation. Among the ... of the anesthetics benzyl alcohol, propofol, chlo-roform and diethyl ether reversed the resistance by acceleration of the passive transport of the drug or dye across the plasma membrane. At these ... anesthetic-medi-ated acceleration of transbilayer drug movement is dueeither to enhanced rate of drug flip-flop across the lipidcore of the membranes or to greater affinity of the drugs for the plasma membrane. ...

Tài liệu Báo cáo khoa học: Competition between innate multidrug resistance and intracellular binding of rhodamine dyes pdf

... under theseconditions, the free concentration of the dyes in the cytoplasm is low compared to the extracellular concen-trations of the dyes. Equilibration of the dyes across the plasma membrane ... in the cytoplasm with their concentration in the exter-nal medium. The protection provided to multidrug resistance cells by ABCtransporters has to overcome competition by passive uptake of the ... comparison of rhodamine uptake, in the presence and the absence of uncouplers, allows the estimation of the effect of intracellular binding on the MDR phenomenon. The data detailed obtained in the present...

Báo cáo khoa học: Highly site-selective stability increases by glycosylation of dihydrofolate reductase ppt

... the changes in free energy of unfolding werebecause of changes in the gradient of the urea depen-dence of the free energy (supporting information),rather than changes to the mid-point of the ... triplicate.Determination of free energy of unfoldingEquilibrium unfolding of the proteins and their deriva-tized glycoforms was monitored in the presence of urea by the ﬂuorescence intensity ... the active site at the end of the FGloop (Fig. 1). Our results suggest that the local envi-ronment of the protein is critically important in deter-mining the effect of the glycosyl chain on...

Tài liệu Báo cáo khoa học: Modulation of a-synuclein aggregation by dopamine in the presence of MPTP and its metabolite pptx

... 1B shows the patternseen after the development of the blot. With increasein time of incubation, the intensity of the band for the monomeric protein decreased, whereas the bands for the higher ... Figure 4A shows the kinetics of aggregation of a-synuclein in the presence of 100 lm MPTP and the effect of 50 lm dopamine on the aggregation process. Dopamine delayed the lagphase of aggregation ... are of a-synuclein incubated alone (A), in the presence of 100 lM MPTP (B), in the presence of 200 lM MPTP (C), in the presence of 100 lM MPP+(D), in the presence of 200 lM MPP+(E), in the...

Tài liệu Báo cáo khoa học: Modulation of F0F1-ATP synthase activity by cyclophilin D regulates matrix adenine nucleotide levels pptx

... inrupture of the outer membrane. The identity of the proteins comprising the PTP is debated; the ubiqui-tous matrix-located protein cyclophilin D (CYPD) isinvolved in the modulation of PTP open ... setting, the ability of the F0F1-ATP synthase topump protons out of the matrix represents the onlycomponent opposing the action of an uncoupler. On the basis of a recent study by Giorgio ... deamination [30]. The lack of oxida-tion of 1 mm glutamate in the presence of 5 mmsuccinate can be demonstrated by a complete lack of effect of rotenone on recordings of membrane poten-tial...

Tài liệu Báo cáo khoa học: Modulation of sterol homeostasis by the Cdc42p effectors Cla4p and Ste20p in the yeast Saccharomyces cerevisiae pptx

... affect sterol biosynthesis dur-ing the formation of a mating projection. Nevertheless, the phenotypes of mutants defective in ergosterolsynthesis clearly demonstrate the importance of sterolsfor ... cleave off the reporter RUra3,which is fused to the PAK. Released RUra3, a modiﬁed version of the enzyme Ura3 with an arginine at the extreme N-terminus, istargeted for degradation by the enzymes ... homologues of oxysterol-binding proteins, a family of proteins that regulate the synthesis and transport of sterols, were found toparticipate in Cdc42p-dependent polarity [30]. Takentogether, these...

Tài liệu Báo cáo khoa học: Modulation of the enzymatic efﬁciency of ferredoxin-NADP(H) reductase by the amino acid volume around the catalytic site pptx

... result of changesintroduced by the mutations in the environment of the prosthetic group. As a result of the important changesobserved for each mutant in the differential spectraelicited by NADP+, ... in the protein stability of our mutants. There-fore, these conclusions strengthen our hypothesis that the catalytic efficiencies of the recombinant enzymesused in our study were related to the ... phe-nol as the tyrosine R group. This system has been usedpreviously to analyze the geometry of the tyrosinestacked on the si-face of the flavin in FNRs [12]. The single point energies of the flavin–tyrosine...

Tài liệu Báo cáo khoa học: Modulation of oat arginine decarboxylase gene expression and genome organization in transgenic Trypanosoma cruzi epimastigotes docx

... During the subsequentperiod, the integration of ‡ 2 units of the transfectedplasmid into the parasite genome seemed to occur, asshown by the production of both DNA segmentsafter ‡ 4 weeks of ... negli-gible values [7,9,10]. These results could be attributedneither to a deﬁcient uptake of the amino acids by the parasites [12] nor to the presence of ODC or ADCinhibitors in the protozoan internal ... beexplained by the concomitant changes occurring in the parasite genome organization.Results and DiscussionExpression of the oat ADC gene in T. cruziIn order to study the expression of the foreign...

Tài liệu Báo cáo khoa học: Modulation of cyclin D1 and early growth response factor-1 gene expression in interleukin-1b-treated rat smooth muscle cells by n-6 and n-3 polyunsaturated fatty acids pdf

... action of EPA and DHA (Eur. J. Biochem. 271) 4465 Modulation of cyclin D1 synthesis andhyperphosphorylation of Rb by n-3 and n-6 PUFAsInduction of cyclin D1 is one of the e arliest effects of mitogenic ... to the S phase. Expression of the cyclin D1 geneseems to be regulated essentially at the transcription level. Itis blocked by inhibitors of the MAPK or P I3-K pathways. The promoter re gion of ... PUFAs by modulating various steps of the inﬂam-matory process. We have investigated the molecular mech-anisms by which the incorporation of the n-6 PUFA,arachidonic acid, increases the proliferation...

Báo cáo khoa học: Modulation of glucocorticoid receptor-interacting protein 1 (GRIP1) transactivation and co-activation activities through its C-terminal repression and self-association domains pptx

... and through modulation of the effects of co-repressors on its repression domains. These are the ﬁrstresults to indicate that the structural components of GRIP1, especiallythose of the C terminus, ... obvious sequence homology, the nature of their downstream targets and the speciﬁccomponents of the transcriptional machinery remainunknown. The mechanisms by which the p160 co-activatorsfunction ... pro-vide insights into the regulatory mechanisms control-ling the functional activities of GRIP1. They extendour understanding of the importance of the structuralstatus of GRIP1 in modulating...

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