Báo cáo khoa học: Hydrogen bond residue positioning in the 599–611 loop of thimet oligopeptidase is required for substrate selection pdf

... to other substrates, the bradykinin derivative is also unaffected byGly mutations in the loop. This distinction suggests that the role of Glyresidues in the loop is to properly orientate these ... among the four substrates tested.This discovery helped reveal the primary role of Glyresidues in the 599–611 loop in positioning the Tyr605and Tyr612 residues needed for substrate hydrolysis. In ... kcat for these three substrates (see Table 1). Molecu-lar modeling of the closed form of TOP showed that the hydroxyl of Tyr612 is within hydrogen bondingdistance of the carbonyl carbon of the...

Tài liệu Báo cáo khoa học: Tryptophan tryptophylquinone cofactor biogenesis in the aromatic amine dehydrogenase of Alcaligenes faecalis Cofactor assembly and catalytic properties of recombinant enzyme expressed in Paracoccus denitriﬁcans pptx

... requires the cooperation of TTQ biogenesis genes from the maugene cluster. By performing detailed kinetic studies of both AADH enzymes, we show that the recombinantenzyme is indistinguishable from the ... owing to the poor buffering capa-city of BisTris propane at this pH. Analysis of the data (omitting the pH 10 data point) using the equa-tion for a double ionization yielded a pKa1value of 7.1 ... Vmax is the maximuminitial velocity, [S] is the substrate concentration andKi is the inhibition constant for substrate. We alsoobserved substrate inhibition with the ‘fast’ substrate tryptamine...

Báo cáo khoa học: Post-translational modiﬁcations in the active site region of methyl-coenzyme M reductase from methanogenic and methanotrophic archaea potx

... function of the methyl group mayinvolved improved orientation of the histidine inside the coenzyme B-binding site. With the methylation, the histidine residue is prevented from forming two alter-nate ... hydrogen bonds of the protein to the phosphate group of coenzyme B. The distance of 2.65 A˚indicates the presence of a strong hydrogen bond with fully overlapping orbitals. Owing to the positive inductive ... andMoaD, involved in thiamine biosynthesis and molyb-dopterin biosynthesis, respectively, and for the sulfura-tion of uridine in tRNA to thiouridine can beenvisaged [34–36]. This mechanism probably...

Báo cáo khoa học: Active site residue involvement in monoamine or diamine oxidation catalysed by pea seedling amine oxidase doc

... v2 of Phe298 is about )30°. In both conformations the unchargedside-chain of Lys296 is hydrogen bonded with the O4 of TPQ.To determine the charged-state of residues involved in substrate binding ... of the substrate. The amino group in the substrate tail, which is positively charged in the pHrange explored, may facilitate the correct positioning of the tail and anchor the substrate at the ... where the neutral forms of these com-pounds predominate.Modelling of substrate PSAO interactionsDocking CAD into the active site revealed that the head amino group is located at the bottom of the...

Tài liệu Báo cáo khoa học: Poly(silicate)-metabolizing silicatein in siliceous spicules and silicasomes of demosponges comprises dual enzymatic activities (silica polymerase and silica esterase) doc

... that hydrogen bonding between the imidazole nitrogen of the conserved His and the hydroxyl of the active-siteSer increases the nucleophilicity of the Ser oxygen,facilitating attack of the hydroxy ... This reac-tion is facilitated by hydrogen bonding between the imidazole nitro-gen of the conserved histidine (His) and the hydroxyl of the Ser.W. E. G. Mu¨ller et al. Silicatein comprises ... spicule-forming cells, the sclerocytes, the first layers of the silica shell of the spicules are formed around the silicatein-based axial filament in specific organelles[14]. The prerequisite for intracellular...

Tài liệu Báo cáo khoa học: Dual P2Y12 receptor signaling in thrombin-stimulated platelets – involvement of phosphoinositide 3-kinase b but not c isoform in Ca2+ mobilization and procoagulant activity pdf

... P2Y12-dependent part of the Ca2+response, indicating thatPI3-Kß is the main isoform in Ca2+signal modulationvia P2Y12. Examination of targets downstream of ACBDFig. 10. PI3-K ß-isoform mediates ... considerable amount of the PIP3formed in plate-lets [21], this may suggest that the PIP3produced bythis isoform leads to plasma membrane binding and,hence, activation of PH domain-containing phospho-lipase ... demon-strated that the phosphoinositide 3-kinase b and not the phosphoinositide3-kinase c isoform is responsible for the prolonged Ca2+response and for the subsequent increases in procoagulant...

Tài liệu Báo cáo khoa học: Domain deletions and substitutions in the modular protein evolution doc

... ProDom, C−terminusLength of the N terminus in % of the deleted domainLength of the C terminus in % of the deleted domainPfam, N−terminus Pfam, C −terminusNumber of occurencesNumber of occurences2500035000550000 ... termini,depending on the number of domains in the proteinand the database selected (Fig. 1). The prevalence of terminal deletions did not depend on the number of domains in proteins, and the ... size of the deleted domain was calculated for the proteins with the complete arrangement. To take into account the variability of the length of the complete domain, the length of the N-terminal...

Tài liệu Báo cáo khoa học: Human intrinsic factor expressed in the plant Arabidopsis thaliana doc

... absorption of vitamin B12facilitating itsinternalization [2,3,5]. Lack or malfunction of this Cblbinder hampers the uptake of the minute amounts of the vitamin present in food. Only around 1% of the ... source of human IF for analytical andtherapeutic purposes.Keywords: arabidopsis; cobalamin; intrinsic factor; recom-binant.Vitamin B12(cobalamin, Cbl) is the most complex of the vitamins [1]; ... University of Aarhus, DenmarkIntrinsic factor (IF) is the gastric protein that promotes the intestinal uptake of vitamin B12. Gastric IF from animalsources is used in diagnostic tests and in vitamin...

Báo cáo khoa học: Adipocyte hyperplasia and RMI1 in the treatment of obesity doc

... modern era, yet existing medicines to combat this globalpandemic are disappointingly limited in terms of safety and effectiveness. The inadequacy of currently available therapies for obesity has ... suggestingthat these cyclin-dependent kinase inhibitors areimportant in the regulation of adipocyte number. The S-phase kinase-associated protein (Skp)1–Cullin-F-box protein (SCF) ubiquitin ligase ... at each phase of the cell cycle byvarious complexes of cell-cycle-related molecules,including cyclins, cyclin-dependent kinases, their inhib-itors and the retinoblastoma protein (RB), as well...

Báo cáo khoa học: Nanoparticles can induce changes in the intracellular metabolism of lipids without compromising cellular viability docx

... novolipid synthesis. The PI3K ⁄ Akt signaling pathway is best known for its role in the maintenance of cell survival, but is alsoresponsible for the up-regulation of glucose metabo-lism and the induction ... resulted in the disappearance of LDs (Fig. 2), suggesting that these cells carriedout lipogenesis (de novo synthesis of lipids) in controlcultures. Interestingly, cerulenin also inhibited LDformation ... induction of lipogenesis [37–40]. Wehypothesized that signaling via the PI3K ⁄ Akt pathwaywas involved in the promotion of the formation of LDs in cells treated with QDs. To test this hypothesis,primary...

Xem thêm