Báo cáo khoa học: Mechanism of the ring contraction process in vitamin B12 biosynthesis by the anaerobe Propionibacterium shermanii under aerobic conditions docx

... 2007)doi:10.1111/j.1742-4658.2007.05880.x The mechanism of the ring contraction process during vitamin B12biosyn-thesis by the anaerobe Propionibacterium shermanii was investigated under both aerobic and anaerobic conditions by ... cultivated in phosphateFig. 2. The mechanisms of the ring contraction process in the biosynthesis of vitamin B12postulated on the basis of the isolation of factor IVfrom the anaerobe P. shermanii. K. ... Mechanism of the ring contraction process in vitamin B12 biosynthesis by the anaerobe Propionibacterium shermanii under aerobic conditions Katsumi Iida, Kuniaki...

Tài liệu Báo cáo khoa học: Mechanism of dihydroneopterin aldolase NMR, equilibrium and transient kinetic studies of the Staphylococcus aureus and Escherichia coli enzymes docx

... DHNA inhibitors. The binding of the inhibitors to the enzymes cause adecrease in their fluorescence intensities. The increasingfluorescence intensities in Fig. 5A were obtained by subtracting the ... obtained in the absence of the ligand was subtrac-ted from the corresponding data set obtained in the pres-ence of the ligand. The Kdvalues were obtained by nonlinear least-squares fitting of ... A set of control datawas obtained in the absence of HPO and was subtracted from the corresponding data set obtained in the presence of the enzyme. The solid lines were obtained by nonlinear...

Báo cáo khoa học: Mechanism of the reaction catalyzed by dehydroascorbate reductase from spinach chloroplasts doc

... represented by the product of the maximum velocity (Vmax) and the concentrations of substrates, and the denominator by the function of the concentrations of substrates. The straight lines of the double-reciprocal ... the kinetic parameters, as described in the Appendix, and summarized in Table 1. The calculated KGSHmwas the sum of the values of Kmfor the ﬁrst-binding molecule of GSH and the second-binding ... thisresidue may be involved in the formation of the disulﬁdebond with GSH in the cysteinyl-thiohemiketal. Other Cresidues might also be involved in the reaction of the spinach enzyme, but their contributions...

Tài liệu Báo cáo khoa học: Roles of AP-2 transcription factors in the regulation of cartilage and skeletal development doc

... helix–span–helix domain at the C-terminus shown in blue medi-ates dimerization and, together with the basic domain, (red) DNA-binding. ‘*’, amino acids that are identical in all sequences in the align-ment; ... expressedduring the preimplantation period, and, with the exception of AP-2a, also in unfertilized oocytes.Furthermore, they determined that functional redun-dancy occurs between these proteins during ... role of AP-2a and AP-2e in chondrogenesis. Overview of the differen-tiation stages during chondrogenesis and the involvement of transcription factors(henatoxylin and eosin-stained section of...

Tài liệu Báo cáo khoa học: Glycation of low-density lipoprotein results in the time-dependent accumulation of cholesteryl esters and apolipoprotein B-100 protein in primary human monocyte-derived macrophages docx

... demonstrated by receptor-blockingexperiments. The rates of uptake of both the lipid andprotein components are not matched by the rate of cel-lular metabolism of these species, resulting in the accu-mulation ... CD36. The accumulation of lipid in thesemacrophages is accompanied by increased endocytosisand degradation of apoB, with the difference in the rates of the latter two processes resulting in accumula-tion ... mediumduring the chase period allows the turnover of preaccu-mulated protein to be studied in the absence of furthercellular uptake. In these studies, cell death was < 12%as measured by the...

Tài liệu Báo cáo khoa học: Mechanism of protection of peroxidase activity by oscillatory dynamics docx

... demonstrating the protective role of oscillatory dynamics, the presentwork concentrates on the mechanism of inactivation of theenzymebyfreeradicalintermediatesandtheroleofaromatic species in this mechanism. The ... help in understanding the origin of the phenomenon. The reason is of course that the changes in concentrations are inherent to the reaction system (i.e. they depend on the entire network of elementary ... weobserve an abrupt termination of the degradation of the enzyme [12], because the inhibition of the reaction alsoblocks the formation of free radicals [28]. Thus, the inactivation of the enzyme can...

Tài liệu Báo cáo khoa học: Localization of N-linked carbohydrate chains in glycoprotein ZPA of the bovine egg zona pellucida pptx

... glycosylated.Determination of the number of N-glycosylation sitesWe then investigated the number of N-glycosylation sitesand the localization of N-linked chains in ZPA using the puriﬁed ZPA. In the 15% gel, the ... mapping on HPLC referring to the reportedstructures of the unfractionated zona protein mixture [14].To obtain the core carbohydrate chains of the acidicchains, the N-linked chains were further ... b-Galactosidase.Therefore, the nonreducing terminal b-Gal residues in the sialidase digests of the acidic fraction in Table 1 have beeneliminated and the monosialylated chains converge on the chains in the...

Báo cáo khoa học: Analysis of Lsm1p and Lsm8p domains in the cellular localization of Lsm complexes in budding yeast ppt

... pro-teins with the exception of LsmDN88p. This suggeststhat each of the Lsm8p domains contributes toproper U6 binding, either directly or indirectly, by affecting the RNA-binding ability of the ... thosewith the C-terminal domain deleted is consistentwith this (Figs 4 and 5). Hybrid proteins carrying the N-terminus of one protein and the Sm domain of the other localize according to the N-terminal ... accumulates in cytoplasmic foci under stress conditions (Fig. 6A). Thus, in the absence of the C-terminal domain, the N-terminal domain, not the Sm domain, determines the subcellular localization. By contrast,...

Báo cáo khoa học: Interaction of human steﬁn B in the preﬁbrillar oligomeric form with membranes Correlation with cellular toxicity doc

... [17,18]. By following the kinet-ics of fibril formation, conditions were defined in which the protein exists in the form of prefibrillaroligomers ⁄ aggregates, which persist during the lagphase. These ... 3.3 bound the most of all, as the signal increase during the injec-tion phase was the largest and there was low dissoci-ation after the end of injection.Discussion The main hypothesis for ... 17.6Fig. 5. Insertion of stefins into DOPC and DOPG monolayers. (A)Kinetic traces of the insertion into DOPG lipid monolayers at initialpressure of 5 mNÆm)1. The proteins were injected into the sub-phase...

Báo cáo khoa học: Kinetics of enzyme acylation and deacylation in the penicillin acylase-catalyzed synthesis of b-lactam antibiotics pptx

... the kinetic constants forhydrolysis and synthesis of penicillin G, ampicillin andcephalexin. Furthermore, insight into the nature of the transition state in the rate-determining steps of the ... aR145:NH2[4,9,34]. In 7-ADCA,which has a dihydrothiazine ring instead of a thiazolidine ring, the 2b-methyl group is not present and due to the moreplanar character of the dihydrothiazine ring, the carboxylategroup ... reactions the structure of the leaving group of the substrate has an effect on the details of the kinetic mechanism. Deacylation by b-lactam nucleophilesSince the rate-limiting step for the hydrolysis...

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