Báo cáo khóa học: Mechanistic insight into the peroxidase catalyzed nitration of tyrosine derivatives by nitrite and hydrogen peroxide doc

... et al.(Eur. J. Biochem. 271) Ó FEBS 2004 Mechanistic insight into the peroxidase catalyzed nitration of tyrosine derivatives by nitrite and hydrogen peroxide Enrico Monzani1, Raffaella Roncone1, ... °C. The inset shows an expansion of the plot in the low nitrite concentration range.Fig. 2. Inhibition of the LPO-mediated phenol nitration by nitrite. Plot of the rate of LPO -catalyzed nitration ... Ho¨nggerberg, Zu¨rich, SwitzerlandPeroxidases perform the nitration of tyrosine and tyrosylresidues in proteins, in the presence of nitrite and hydrogen peroxide. The nitrating species is still...

Báo cáo khoa học: Structural insight into the evolutionary and pharmacologic homology of glutamate carboxypeptidases II and III ppt

... works 4453 of the S1-bound chloride anion and ‘pushes’ the Cl)out of the bottom of the S1 pocket (the occupancy of the Cl)in this structure is 0.7). The alternate confor-mation of the Asp443 ... with the occupancy of the S1 pocket by a ligand and the ‘open–close’ transition exploits the hinges on the twosides of the lid made up of Asn540 ⁄ Trp541 and Gly548 (GCPII numbering). In the ... consisting of sevenb-strands ﬂanked by eleven a-helices. The apicaldomain (or the protease associated domain) is inserted into the protease domain and features a (3 + 4)-stranded b-sandwich ﬂanked by...

Tài liệu Báo cáo khoa học: Structural insights into the substrate speciﬁcity and activity of ervatamins, the papain-like cysteine proteases from a tropical plant, Ervatamia coronaria ppt

... erva-tamin-A, the P3 moiety of both the molecules of the asymmetric unit runs along the extended backbone of residues 65–64 and is partly exposed to the solvent(Fig. 2B). On the other hand, the P3 ... proton from the catalytic Cys pres-ent at the N-terminus of the helix to the His of the dyad [19,50,51]. The ﬁrst stage of catalysis is mediated by the highly active thiolate ion of the Cys. Biochemi-cal ... at the bottom of the subsite is conservedin ervatamins. Compared to a Ser in the equivalentposition of papain, the role of Leu here is to restrict the size and depth of the S2 subsite. The...

Tài liệu Báo cáo khóa học: Further insights into the assembly of the yeast cytochrome bc1 complex based on analysis of single and double deletion mutants lacking supernumerary subunits and cytochrome b pdf

... enveloped by subunit 7. The arrowslabeled (b) and (c) point to the areas of interaction between the transmembrane helix of subunit 8 and helices G and H1 of cytochrome b and between the N-terminus of ... membrane or lack of detection of the truncated protein by the antibodies.In the W303–1B q° strain the amounts of the other twocatalytic subunits, cytochrome c1 and the ISP, were reduced by about 70–80% ... panels A and B and the relative amounts of each of the subunits determined by densitometry scanning of the stained Westernblots of the q° and CKL57 membranes are shown in panels C and D, respectively.Ó...

Báo cáo khoa học: New insights into the functions and N-glycan structures of factor X activator from Russell’s viper venom pot

... plate-lets and endothelial cells. The important role of theseglycans in pharmacokinetics has been demonstrated by the slower and smaller increment of FDP in vivo after the injection of desialylated ... the b-Man residue at the C4 position. Finally, an H ion would be formedthrough concerted loss of the substituents on the 6-arm and the bisecting GlcNAc. The identiﬁcation of Lex and SLex by ... sequenced. Of these, 10clones were found to encode the LC2 and LC1 sub-units. Others were found to encode other variants of the C-lectin-like venom proteins. The amino acidsequences of both subunits...

Báo cáo khoa học: New insights into the P-glycoprotein-mediated efﬂuxes of rhodamines doc

... the cytosol. This observation allows the further determination of the concentration of drug free in the cytosol of resistantcells. The determination of karequires also the measurement of the ... the rate of passive diffusion of the dye through the plasma membrane. This cannot be done by the simplemeasurement of the increase of the ﬂuorescence signal(Fcyto) of the cells when they are ... Na+-buffer on the one hand and K+bufferon the other hand. In Na+-buffer a strong decrease of the ﬂuorescence signal was observed due to the accumula-tion of the lipophilic cation mainly in the mitochondrialcompartments,...

Tài liệu Báo cáo khoa học: Poly(ADP-ribose) The most elaborate metabolite of NAD+ Alexander Burkle pptx

... motif, they are both targeted to the nuc-leus, and they bind to and become activated by DNaseI-treated DNA. Both PARP-2 and PARP-1 can homo- and heterodimerise, and both are involved in the baseexcision ... by many groups.Attractive scenarios developed over the last couple of years are (a) the localized relaxation of chromatin at the site of DNA damage, mediated either by direct modiﬁ-cation of ... comprehensive picture of the biological functions of poly(ADP-ribosyl)ation and the underlying molecular mechanisms is highly desirable and would further accelerate the transfer of basic sci-entiﬁc...

Tài liệu Báo cáo khoa học: Proton transfer in the oxidative half-reaction of pentaerythritol tetranitrate reductase Structure of the reduced enzyme-progesterone complex and the roles of residues Tyr186, His181 and His184 pdf

... conditions. The redox state of the PETN crystals could easily by assessed and veriﬁed by bright yellow colour of the oxidized crystalsvs. the colourless reduced form. All data were processed and scaled ... above the si face of the FMN isoalloxa-zine ring and are held in position by hydrogen bondinteractions with His181 and His184 [2]. These residuesalso form interactions with the hydroxyl group of ... and indicate re-oxidation of the ﬂavin and the formation of the hydride-Meisenheimercomplex of TNT. (C) As for panel B except the spectral changes are recorded over an extended time period and...

Tài liệu Báo cáo khoa học: A role for the intersubunit disulﬁdes of seminal RNase in the mechanism of its antitumor action docx

... mechanism of antitumouraction of BS-RNase is based on the ability of the proteinto resist the neutralizing action of the cytosolic RNaseinhibitor, a resistance due to the dimeric structure of the enzyme. ... approaches [4], and explained [4–6] by the resistance of the enzyme in its dimeric state to the inhibitory action of CRI (the cytosolic RNase inhibitor).When the structure of CRI [7] and CRI complexed ... thatlink the two subunits of BS-RNase. Monomeric derivatives of the protein are inactive as cytotoxic agents when they areprepared by reductive cleavage of the intersubunit disulﬁdes and the resulting...

Tài liệu Báo cáo khoa học: Moult cycle-related changes in biological activity of moult-inhibiting hormone (MIH) and crustacean hyperglycaemic hormone (CHH) in the crab, Carcinus maenas From target to transcript ppt

... investigated the biological activities of these neuropeptides in the crabCarcinus maenas, at the target tissue, receptor and cellularlevel by bioassay (inhibition of ecdysteroid synthesis),radioligand ... MIH or CHHduring the moult cycle is not at the receptor level.In view of these observations, we also investigated levels of MIH and CHH peptides in the sinus gland and levels of transcripts in ... control lieswithin the signalling machinery of the target tissue, thatexpression and biosynthesis of both neuropeptides is con-stant during the moult cycle, and are not central to the currently...

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