Báo cáo khoa học: Mercury(II) binding to metallothioneins Variables governing the formation and structural features of the mammalian Hg-MT species pptx

... Mercury(II) binding to metallothioneins Variables governing the formation and structural features of the mammalian Hg-MT species A`ngels Leiva-Presa, Merce`Capdevila and Pilar Gonza`lez-DuarteDepartament ... n the effect of two variables, the reaction time and the presence of chloride ions, on the stoichiometry, stereochemistry and degree of folding of the Hg(II)-MT species formed by either the binding ... stereo-chemistry and degree of folding of the species formed. Thus, to understand the reaction pathways followed by Zn-MT and apo-MT species in the presence of Hg(II), the e ffect of each of the previous variables...

Tài liệu Báo cáo khoa học: Calcium-binding to lens bB2- and bA3-crystallins suggests that all b-crystallins are calcium-binding proteins pptx

... cal-cium displaces the dye bound to calcium -binding sites of the protein. Other proteins of this superfamily,namely c-crystallin [20] and AIM1-g1 [15] also induce the J band of the dye indicating ... 492 and 547 nm (Fig. 3). The enhancedluminescence of terbium in the presence of these crys-tallins indicates that Tyr and Trp residues are in the vicinity of the calcium -binding site. The sequence ... ﬁltration and dynamic lightscattering of the apo and holo forms of bA3- and bB2-crystallins. There was no signiﬁcant change in the stability and hydrodynamic radius of the both forms of proteins...

Tài liệu Báo cáo khoa học: Covalent binding to glutathione of the DNA-alkylating antitumor agent, S23906-1 doc

... the bionucleophiles DNA and GSH. The covalent binding of the drug to GSH reduced the formation of DNA adducts and slightly decreased the cytotoxic potential of the molecule. There is now little room ... residues at the N2 position in double-stranded DNA [11]. The covalent binding to DNA isapparently responsible for the cytotoxic action [12] and the capacity of the drug to trigger apoptosis in ... activity and DNA-alkylation ability of the agent, even in the presence of highlevels of GSH. Covalent binding to GSH has also beenobserved with the drug mitomycin C (MC) [28,29]. The formation of...

Báo cáo khoa học: Ibuprofen binding to secondary sites allosterically modulates the spectroscopic and catalytic properties of human serum heme–albumin doc

... 2011 FEBStion of the heme Fe, as the result of the conforma-tional transition following ligand binding to FA2 [18]. The present considerations appear to apply only to ibuprofen, as other Sudlow ... named the heme site) and the FA2 (corresponding to the regulatory site of the neutral -to- basic conformationaltransition) pockets display high afﬁnity for FAs [17].Therefore, the effect of FAs ... at the heme -binding pocket (FA1). Indeed, ibuprofen binding to HSA–hemehas been reported to induce the hexa-coordination of the heme Fe atom [18,21,23]. Thus, peroxynitrite can-not bind to the...

Báo cáo khoa học: Nucleotide binding to human UMP-CMP kinase using ﬂuorescent derivatives ) a screening based on afﬁnity for the UMP-CMP binding site potx

... as fluorescent probes to monitor the binding of nucleotides to UCK. These assays wereused to determine the binding affinity of bisubstrates and new phosphonate analogs and to validate a fluor-escent ... screening of newcompounds.Results and DiscussionCompetitive fluorescence experiments to determine the binding of natural substrates to the donor and the acceptor sites of human UCK The ATP -binding ... 6. Model of the acceptor -binding site in the closed form of human UCK. (A) Superposition of the acceptor site with bound CMP (blue) and cidofovir (red). (B) Superposition of the acceptor site...

Báo cáo khoa học: Copper-containing nitrite reductase fromPseudomonas chlororaphis DSM 50135 Evidence for modulation of the rate of intramolecular electron transfer through nitrite binding to the type 2 copper center pot

... CoCl2,0.6andNa2B2O7,0.1. The optical density, the concentrations of nitrate [17] and nitrite [18], the pO2 and the pH of the medium weremonitored, and the composition of the gaseous phase in the fermentor was ... and Shain, and plotted vs. the inverse of the scan rate. The plotsyielded straight lines, conﬁrming the applicability of the Nicholson and Shain theory to the present system, and the variation of the ... center of the enzyme. These modiﬁcations may beattributed to either the presence of the substrate and/ or aproduct in the vicinity of the T2Cu active center rather than to disruption of this...

Báo cáo khoa học: Docosahexaenoic acid stabilizes soluble amyloid-b protoﬁbrils and sustains amyloid-b-induced neurotoxicity in vitro ppt

... charges; in the case of Ab, the arginine atposition 5, and the lysines at positions 16 and 28.Interestingly, the formation of fibrils by association of protofilaments has been proposed to involve ... pH.As protofibrils and other oligomeric species of Abhave been found to be toxic [3–5,28,29], and DHAtreatment stabilized soluble protofibrils, we examinedwhat effects the interaction of DHA with ... detail. Therefore, we have investi-gated the effect of unsaturated DHA and AA and the saturated fatty acid arachidic acid (20:0) on Ab mono-mer oligomerization into protofibrils and protofibril...

Báo cáo khoa học: 15-Deoxy D12,14-prostaglandin J2 suppresses transcription by promoter 3 of the human thromboxane A2 receptor gene through peroxisome proliferator-activated receptor c in human erythroleukemia cells ppt

... provide further evidence for the role of PPARc in the regulation of TP gene expression within the vasculature and point to further critical differencesinto the modes of regulation of TPa and TPb ... Similar to the EMSAs involving the extended PPARc ⁄ RXR probe A, nuclear factor bind-ing was independent of 15d-PGJ2stimulation. The lig- and independent nature of the nuclear factor binding to ... owing to the inability to transfectHEL cells to high efﬁciency for RNAi and due to the failure of CHIP analysis to discriminate between the PPARc ⁄ RXR site located between )159–148 and the adjacent...

Báo cáo khoa học: Bistability from double phosphorylation in signal transduction Kinetic and structural requirements potx

... e1Wa,e1Wb,e2Wb and e2Wcare the M-M com-plexes. WT and eiTare the total concentration of the interconvertible protein and the total concentration of the catalyst, respectively. Note that only the formation of ... on the ratio between the product of the catalytic constant of cycle 1 (steps 1 and 2) and cycle 2(steps 3 and 4) (Eqn 7) and the values of a, c and bonly depend on the KSvalue (Eqn 8). The ... different values of the product of r31r24at ﬁxed KSvalues (Fig. 2). Thisproduct is called the asymmetric factor (H) and is the ratio of the product of the catalytic constants of the steps that...

Báo cáo khoa học: Activator-binding domains of the SWI ⁄ SNF chromatin remodeling complex characterized in vitro are required for its recruitment to promoters in vivo pot

... activation by galactose To determine whether the activator -binding domains of the SWI ⁄ SNF complex are important for its recruit-ment to promoters in vivo and to determine whether the Swi1 and Snf5 domains ... activation of these genes within the same time window. The activator -binding domains in the Swi1 and Snf5 subunits of the SWI ⁄ SNF complexare essential for recruitment of the SWI ⁄ SNF complex to these ... recruiting function of the Swi1 and Snf5 activator -binding domains. The in vivo validation of the Swi1 and Snf5 activator-bind-ing domains is also of interest in relation to the two-step binding mechanism...

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