Báo cáo khoa học: The bioactive dipeptide anserine is transported by human proton-coupled peptide transporters doc

... The bioactive dipeptide anserine is transported by human proton-coupled peptide transporters Stefanie Geissler1, Madlen Zwarg1, Ilka Knu¨tter1, ... at the intestinal epithelium. The purpose of this study was to investigate whether anserine is a substrateof the H+⁄ peptide cotransporters 1 and 2 (PEPT1 and PEPT2). We ﬁrstassessed the ... revised 2December 2009, accepted 2 December2009)doi:10.1111/j.1742-4658.2009.07528.x The bioactive dipeptide derivative anserine (b-alanyl-1-N-methyl-l-histidine) is absorbed from the human...

Tài liệu Báo cáo khoa học: The kinetic properties of various R258 mutants of deacetoxycephalosporin C synthase doc

... uncharged stateor that the positive charge is no longer proximal to the cosubstrate side-chain. This result is consistent with loss ofactivity in this mutant when 2-OG is used as the cosubstrate.Higher ... uncouplingof the two reactions, i.e. the stoichiometry is less than 1 : 1.Comparison of the results for assays 1a and 2a imply that the level of 2-OG conversion is greater than penicillin Gconversion by ... interactionbetween the lysine side-chain and 2-OG. The R258Hmutant retained little activity with 2-OG, which wassurprising in light of the results with the R258K mutant.This probably arises due to the R258H...

Báo cáo khoa học: The purine derivative PI-55 blocks cytokinin action via receptor inhibition docx

... to develop their agonists and antagonists. In the present study, we report the identiﬁcation of the ﬁrst known moleculeantagonizing the activity of the plant hormone cytokinin at the receptorlevel. ... proteins[17]. The results obtained in the present study furthersupport the hypothesis that the receptors have differentstructural requirements for the stereochemical or phys-icochemical features of the ... example of the strategy for the selection of the candidate cytokininantagonist is summarized in Table 1. It is well knownthat a hydroxyl group placed in the ortho- position, incontrast to the meta-...

Báo cáo khoa học: "The Treegram Index An Efficient Technique for Retrieval in Linguistic Treebanks" docx

... are (labeled) rooted MTs where children are distin- guished by their position. Let s and t be two MTs; t contains s (written as s ~ t) if there exists an in- jective embedding such that (1) ... T(DB, g). The set of all database trees that contain every query treegram. (3) Compute the result set R = {t E Cand~(q)l q ! t}. The costly operation in this approach is the last containment ... TG(t,h) denote the set of all tree- grams of height h contained in the MT t, and let T(DB, g) denote the set of all database trees that contain the treegram g. Assume that g has the height h...

Báo cáo khoa học: The ferredoxin-NADP+ reductase ⁄ferredoxin electron transfer system of Plasmodium falciparum docx

... the His-tag, the mixture was loaded again on the Ni2+–Sepharosecolumn. Owing to the moderate intrinsic afﬁnity of PfFNRfor the nickel ion, the enzyme was retained by the columneven in the ... apicoplast-localised electron transfer pathway involved in the isoprenoid biosynthesis of Plasmodium falciparum.FEBS Lett 579, 6433–6438.8 Wiesner J & Jomaa H (2007) Isoprenoid biosynthesis of the ... power for the synthesis of isoprenoid precursors.These proteins are attractive targets for the development of novel drugsagainst diseases such as malaria, toxoplasmosis, and coccidiosis. We haveobtained...

Báo cáo khoa học: The equinatoxin N-terminus is transferred across planar lipid membranes and helps to stabilize the transmembrane pore pot

... tomean that the His-tag is translocated to the trans sideof the membrane and then blocks the channel whennegative voltages are applied. This is likely, because the His-tag with the linker possesses ... translocate the His-tag at the N-terminal region across the lipidmembrane. The same occurs in the case of EqtII; how-ever, the pore formation efﬁciency of His6–EqtII is reduced, as this mutant is ... 3B).To further evaluate the charge distribution through the pore and possibly the position of the N-terminus, the current–voltage characteristic (I ⁄ V) was studied(Fig. 3C). The symmetry of the I...

Báo cáo khoa học: The speciﬁc delivery of proteins to human liver cells by engineered bio-nanocapsules doc

... 5B). Human hepatocyte speciﬁc delivery of EGFP by infection The preS1 peptide displayed on the surface of L parti-cles recognizes the speciﬁc receptor present on human hepatocytes and is essential ... of the S region is rich in hydrophobicresidues. Therefore, the computer-assisted predictionassumes that there should be two a helices, whichtraverse the ER membrane twice [11,18]. In this ... fraction of the supernatant was furtherimmunoprecipitated with the anti-S IgG conjugated toa microparticle, the L fusion protein band was stilldetected in the fraction, thereby indicating the presenceof...

Báo cáo khoa học: The mitochondrial protein frataxin is essential for heme biosynthesis in plants potx

... evidence exists on the role of thisprotein in the biogenesis of heme-containing proteins inplants. To gain insight into this process, we decided tostudy the role of frataxin using the enzyme ... especially in photosyntheticorganisms. Iron as a cofactor is involved in many cel-lular processes: (a) biogenesis of Fe–S proteins accom-plished by the Fe–S cluster machinery located in the mitochondrial ... suggest-ing that the iron used in heme synthesis is under the control of YFH [21]. Furthermore, yeast mutants withdeﬁciencies in the mitochondrial Fe–S cluster assemblymachinery display reduced...

Báo cáo khoa học: The leech product saratin is a potent inhibitor of platelet integrin a2b1 and von Willebrand factor binding to collagen pdf

... preventhemostasis in the host during hematophagy. In this article, we describe the molecular mechanisms underlying the ability of the leech product saratinto inhibit platelet binding to collagen. In the ... with the process of hemostasis has allowed the leech to continue its alimentary habit of hemato-phagy. The presence of anticoagulants in the salivaryglands of the leech, Hirudo medicinalis, ... interestingly, these platelets wereunable to form lamellipodia (Fig. 5A). Moreover, the presence of either the a2b1mAb 6F1 or saratin abro-gated this adhesion (Fig. 5A), further demonstratingthe...

Báo cáo khoa học: The thermodynamic analysis of protein stabilization by sucrose and glycerol against pressure-induced unfolding The typical example of the 33-kDa protein from spinach photosystem II docx

... contribution to the theoretical P1/2shift, suggesting that the DV change,caused by the sucrose or glycerol was associated with the protein stabilization. The origin of the DV change is discussed. The ... these agents, is the samestabilization mechanism involved when the denaturation is induced either by chemical denaturants or by hydrostaticpressure?To answer these questions the effect of ... caused by effects on DG and DVP1/2, the pressure at which 50% of the protein is unfolded, is a parameter often used to evaluate protein stability. The higher is P1/2, the more stable is the...

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