Báo cáo khoa học: Critical roles of conserved carboxylic acid residues in pigeon cytosolic NADP+-dependent malic enzyme docx

... 2006 FEBS 4081 Critical roles of conserved carboxylic acid residues in pigeon cytosolic NADP+-dependent malic enzyme Shuo-Chin Chang1*, Kuan-Yu Lin1*, Yu-Jung Chen1, Chin-Hung Lai1, ... examine thecontribution of these three amino -acid residues tometal ion binding and enzymatic catalysis. In this study, we sought to delineate the possible roles of these conserved residues in ... hydroxy proton of l-malate in the enzy-matically active complex. In conclusion, we have described the functional roles of these conserved carboxylic acid amino -acid residues using site-directed...

Tài liệu Báo cáo khoa học: Critical roles of Asp40 at the haem proximal side of haem-regulated phosphodiesterase from Escherichia coli in redox potential, auto-oxidation and catalytic control doc

... protein.Additionally, spin states of the Fe(III), Fe(II) andFe(II)-CO complexes of Asp40 mutants were similar tothose of the wild-type enzyme in that all mutant proteinswere in the six-coordinated ... ncubated for 10 minprior to spectroscopic measurements.Cyanide bindingThe association rate of cyanide to haem was observed bymonitoring changes at 417 nm in spectra of the haemprotein in 50 mMTris/HCl ... sensor enzyme composed of two functional domains: an N-terminal haem-boundsensor domain and a C-terminal PDE catalytic domain[1,2]. Catalysis by this enzyme is regulated by the haemredox state in...

Báo cáo khoa học: Critical roles of Leu99 and Leu115 at the heme distal side in auto-oxidation and the redox potential of a hemeregulated phosphodiesterase from Escherichia coli pptx

... characteristic of the heme distal sidecontributes substantially to the ligand binding kinetics of the PAS domain of Ec DOS, as it does in myoglo-bin and hemoglobin. Examination of the effects of these ... phase of the L99F mutant was independent of the O2concentration.bMeasurement of the rate of O2binding was notfeasible because of low heme binding afﬁnity and instability of theprotein.ACBDFig. ... stableFe(II)–O2complex.CO binding kineticsWe next examined the kinetics of CO binding for themutant proteins of Ec DosH using laser ﬂash photo-lysis (Fig. 6 and Table 4). The changes in the Soretregion of the...

Báo cáo khoa học: Different roles of two c-tubulin isotypes in the cytoskeleton of the Antarctic ciliate Euplotes focardii Remodelling of interaction surfaces may enhance microtubule nucleation at low temperature doc

... longitudinal interactions formed by c-T1 and c-T2.Finally, c-T2 possesses a glycine at position 72 in place of consensus ⁄ c-T1 arginine (Fig. 4B¢). This substitutionmay ‘open’ the nucleotide-binding ... whereas the level of the c-T1 transcriptremained unchanged. Ninety-eight percent of the cellswere undergoing mitosis ⁄ cytokinesis at this time (asdetermined by counting of cells using a stereomicro-scope). ... participates in the assembly of the mitotic spindle of E. focardii and that both isotypes are involved in the nucleation of other microtubule structures.Finally, we examined the distribution of E....

Báo cáo khoa học: Crosstalk between Src and major vault protein in epidermal growth factor-dependent cell signalling docx

... Src–SH2binding protein. We observed that MVP interactswith Src in mammalian cells and inhibits the activity of Src tyrosine kinase.ResultsIsolation of MVP as Src–SH2 interacting proteinby GS–SH2 ... ERK activation in Src over-expressing cells. To our knowledge, this is the ﬁrst report of MVP interact-ing with a protein tyrosine kinase involved in a distinct cell signallingpathway. It ... MVP to be a novel substrate of Src and phosphorylated in anEGF-dependent manner. Interestingly, puriﬁed MVP inhibited the in vitrotyrosine kinase activity of Src in a concentration-dependent...

Báo cáo khoa học: Respective roles of the catalytic domains and C-terminal tail peptides in the oligomerization and secretory trafﬁcking of human acetylcholinesterase and butyrylcholinesterase potx

... theprocessing and the activity of AChE and BChE, notablythose involving charged residues, the presence in peptideb of an additional tryptophan (W8) and the presence of six instead of ﬁve residues ... counterparts, in agreement with thehigher mass of BChE subunits [37]. This indicates apredominant in uence of the catalytic domain onoligomerization.Role of the C-terminal cysteineMutation of the ... PRAD-containingproteins, because addition of a t peptide at the C-ter-minus of green ﬂuorescent protein or alkaline phos-phatase allowed the formation of tetramers associatedwith an N-terminal...

Báo cáo khoa học: Critical role of the plasma membrane for expression of mammalian mitochondrial side chain cleavage activity in yeast pptx

... results in an increased level of free sterol (Fig. 4B),and it would also be expected to increase the cycling of sterols by esteriﬁcation and hydrolysis, resulting in anincrease in intracellular ... complementary roles in maintainingfree ergosta-5-enol at appropriate levels, reminiscent of themechanism reported for cholesterol in adrenal cells ([40,54]). In addition to normally cycling between ... [63]. In conclusion, we have used steroid-producing S. cere-visiae strains to study the different factors involved in theSCC of ergosta-5-eneol into pregnenolone, including theeffect of the...

Báo cáo khoa học: Different roles of functional residues in the hydrophobic binding site of two sweet orange tau glutathione S-transferases pdf

... heterodimers of subunits ranging from 23 to30 kDa in size. Subunits of all known GST structuresexhibit a two-domain fold, the N-terminal domain andC-terminal domain, including the highly conserved GSH-binding ... arrangement of these elements is usuallybababba, similar to the thioredoxin fold of otherGSH-binding or cysteine-binding proteins. The H-siteis entirely helical, with a variable number of a-helices,depending ... andmembers of this class overlap in their function of enhancing crop stress tolerance. Despite the important roles of the GSTUs, extensive analysis of critical resi-dues in both domain sites is...

Báo cáo khoa học: New roles of ﬂavoproteins in molecular cell biology: Blue-light active ﬂavoproteins studied by electron paramagnetic resonance pptx

... surprisingly accurately by ENDOR. His365(the analog amino acid of His354 in X. laevis)isindeed located in the binding pocket nearby the H(1¢)proton. Moreover, His369 (the analog amino acid of His358 ... the protein consists of an a ⁄ b-domain and a FAD-binding domain. Thebinding pocket, which is smaller but deeper than those of CPD photolyases, is strictly hydrophobic and con-tains conserved ... couplings from protons whosenuclear spins are interacting only very weakly with theunpaired electron spin, e.g. protons from the proteinbackbone within the cofactor binding pocket, protonsof...

Báo cáo khoa học: New roles of ﬂavoproteins in molecular cell biology: Histone demethylase LSD1 and chromatin pot

... proximity of the ﬂavin ring of theFAD cofactor and extends along the substrate-bindingdomain. Despite the similar overall folding topology in the AOD enzymes, there is signiﬁcant variability in thesize ... is in agreement with the domain organiza-tion in the ﬁrst line. The third line shows a summary of the identiﬁed linear motifs (after ﬁltering processing taking in account the accessibi-lity of ... experiments in MAO B demon-strated that these aromatic residues may have a stericrole in substrate binding and in increasing the nucleo-philicity of the substrate amine moiety [43]. In LSD1one of...

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