Báo cáo khoa học: Irreversible cross-linking of heme to the distal tryptophan of stromal ascorbate peroxidase in response to rapid inactivation by H2O2 ppt

... Irreversible cross-linking of heme to the distal tryptophan of stromal ascorbate peroxidase in response to rapid inactivation by H2O2Sakihito Kitajima1, Taise Shimaoka2, ... isoform is irreversibly cross-linked to a tryptophan residue facing the distal cavity. Mutation of this tryptophan to phenylalanine abolished the cross-linking and increased the half-time for inactivation ... the basis of these results, we propose that the rapid inacti-vation of tsAPX is at least partly due to repositioning of heme caused by cross-linking between heme and the distal tryptophan resulting...

Tài liệu Báo cáo khoa học: Ionic strength and magnesium affect the speciﬁcity of Escherichia coli and human 8-oxoguanine-DNA glycosylases pdf

... for the THF:A ligand. The presence of Mg2+hadlittle effect on the binding of Fpg to the THF:C ligandand slightly improved binding to the THF:A ligand,making it comparable with binding to ... Thus, to address the in uence of the reaction conditions on the binding of Fpg and OGG1 to damaged DNA, we determined Kdvalues for bindingunder the same conditions as used for the kinetic ... experi-ments. In these experiments, ﬂuorescence titration was the method of choice because it allows full control over the composition of the reaction mixture. To minimize the impact of protein binding to...

Báo cáo khoa học: Structural and thermodynamic insights into the binding mode of ﬁve novel inhibitors of lumazine synthase from Mycobacterium tuberculosis pptx

... between the aromatic pyrimidine ring and the indole group of Trp27 should to be weaker in comparison with the purinetrione inhibitors due to the smaller size of the pyrimidine ring. It has in addition ... conditions, theseapparent values can be used for comparison of bindingafﬁnities of the inhibitors under study. The ﬁtting of the binding isotherms of all ﬁve com-pounds with a binding model assuming ... proteinatoms made by the hydroxyl groups of the ribitylchain in the other structures. Moreover, several directcontacts with the protein chain by the nitrogen atomsand keto groups of the purinetrione...

Báo cáo khoa học: DNA polymerase e associates with the elongating form of RNA polymerase II and nascent transcripts pot

... treatment, (b) correlation of the interaction with phosphorylation of Ser5 of the C-terminal domain hepta-peptide repeat, and (c) the ability of C-terminal domain kinase inhibitors to abolish it. Polymerase ... aschromatin remodelling factors [2]. The carboxy-ter-minal domain (CTD) of RNA pol II has been implica-ted in mediating interactions with other factorsinvolved in transcription and mRNA processing, ... iod-ide-stained cells [65] in parallel cell cultures. Where indi-cated, cells were cultured in the presence of the indicatedconcentrations of one of the following inhibitors:20 lgÆmL)1a-amanitin,...

Báo cáo khoa học: Akt-dependent phosphorylation negatively regulates the transcriptional activity of dHAND by inhibiting the DNA binding activity pdf

... expressed in 293Tcells became phosphorylated, possibly at its Akt phos-phorylation motif, in the absence of kinase inhibitors,whereas the phosphatidylinositol 3-kinase inhibitor wort-mannin and the ... DNA binding activity of dHAND could beaffected by Akt phosphorylation. The in uence of phos-phorylation by Akt on the DNA binding activity wasexamined by gel shift analysis. We included the ... using anti-HA Ig and the kinase reaction was started by adding GST-dHAND to the immunoprecipitants in the reaction buffer containing [32P]ATP[cP]. As shown in Fig. 2, strong incorporation of 32P...

Báo cáo khoa học: Homoadenosylcobalamins as probes for exploring the active sites of coenzyme B12-dependent diol dehydratase and ethanolamine ammonia-lyase docx

... adenine ring of AdoCbl on those of the enzyme-bound AdePeCbl isnot possible without cleavage of the Co-C bond. The adenine ring of the coenzyme would be accommodated to the adenine-binding pocket ... binding to the enzyme in the pres-ence of ethanolamine, although they showed red orblue shift of the a-band by less than 6 nm (Fig. 3J–L). The steady-state concentrations of cob(II)alamin inter-mediate ... pocket in order to obtain the maximal binding energy. Supposing AdoCbl is tightlybound by the enzyme at both the cobalamin moietyand the adenine ring, marked distortions, namely bothFig. 4. Photostability...

Báo cáo khoa học: Alternative binding proteins: Anticalins – harnessing the structural plasticity of the lipocalin ligand pocket to engineer novel binding activities pdf

... in the hydrophobic interior of lipocalins – but rather servefor cross-linking the N- and C-terminus to the b-barrel[5] – they are not as crucial for folding as is the casefor immunoglobulins. ... anddigoxigenin are bound at the bottom of the cleft thatharbours biliverdin IXc in the BBP [24]. Thus, while the overall topology of the lipocalin, comprising the b-barrel with the a-helix attached to ... with the BBP. These structural changes seem to be triggered by the amino acid substitutions thatwere introduced during the combinatorial engineering of the anticalins rather than by complex formationwith...

Báo cáo khoa học: Temperature and salts effects on the peptidase activities of the recombinant metallooligopeptidases neurolysin and thimet oligopeptidase pdf

... for the hydrolysis by TOP of the peptides containing Ile, Val and Asp deviated from the linearity above 25 °C. The plot for the reaction of the peptide containing Ala with TOP was not linear in ... doi:10.1046/j.1432-1033.2002.03129.xLeu-enkephalin from the enkephalin-containing peptides[22], and the speciﬁc TOP inhibition increased Met-enke-phalin antinociception in rodents [23]. TOP and neurolysinare able to hydrolyze the biologically ... Val position in order to verify the in uence of the nature of the amino acid at this position ondetermination of the cleavage sites and on the amount of their hydrolysis. This series of peptides...

Báo cáo khoa học: A possible physiological function and the tertiary structure of a 4-kDa peptide in legumes potx

... As the capability of binding of insulin and the 4-kDa peptide to the 43-kDa protein is similar, in our previous paper we named the 4-kDa peptide as leginsulin. But the 4-kDa peptide is not insulin, ... wereprepared by the Escherichia coli protein expression system. The assay of binding activity of the mutant 4-kDapeptides to the 43-kDa protein was carried out by ligandblotting. The 43-kDa protein was ... residue-peptide which can induce the transcription of the tomato protease inhibitor gene in response to insect damage [34]. The systemin signal has beenconsidered to be transduced through the octadecanoidFig....

Tài liệu Báo cáo khoa học: A systems biology approach for the analysis of carbohydrate dynamics during acclimation to low temperature in Arabidopsis thaliana doc

... successful metabolic engineering of freezing tolerance in plants should include such ananalysis of the dynamics of metabolism to gain com-prehensive information about the effects of individualoverexpression ... arereversibly interconnected. The rate of sucrose export to sink organs (rSuc ﬁ Sinks)was calculated as the difference between the spline-interpo-lated rates of net photosynthesis and of changes in the carbohydrate ... 3F).Cold-induced changes in net carbon uptake andsink export To obtain a quantitative measure of how exposure to 4 °C in uenced the process of photosynthesis, gasexchange of plants was measured by infrared...

Xem thêm