the mechanism of fermentation

... to study the binding of ATP alone to the protein were unsuccessful, as the protein precipitated upon addition of ATP in the absence of pantoate. An important feature of the NMR study is the fact ... [8,9]. One of the interesting features of the plant PSs is the presence of a conserved 24 residue insertion in the sequence [9]. This sequence of amino acids, which is missing in the sequence of bacterial ... pantothe- nate from low amounts of pantoate [9]. Here, we report the results of the structural studies of the panto- ate-bound form of the N-terminal domain of E. coli PS (nPS). The structure and substrate-binding...

Ngày tải lên: 16/02/2014, 09:20

... for the initial decrease of the oxalo- acetate concentration in t he equilibrium due to the accumulation of NADH [25]. Lineweaver–Burk diagrams were obtained b y use of the worksheet of the program EXEL 98 ... propionyl-CoA in the DmcsA-strain, the activity of methylisocitrate lyase is twice as high than that of the wild-type. The addition of acetate to these media not only lowered the propionyl-CoA ... branch of the pentose phosphate pathway. This was determined by the use of glucose-6-phosphate as the substrate and NADP as the hydrogen acceptor. Due to the use of cell-free extracts, not only the...

Ngày tải lên: 19/02/2014, 16:20

... some deviation from the geometry optimal for the abstraction of the a-proton. For the reaction of TPL with L -methio- nine the rate of abstraction of the a-proton, leading to formation of the quinonoid ... (b) the statistical factor taking account of the ratio of protons and deuterons on the considered group when the latter is polyprotic; (c) the degree of restriction of the free rotation of the ... positions of the a-proton and the side chain of any bound amino ac id. The lability of the a-proton observed for a large number of amino acids [5] under the action of TPL gives evidence for the orthogonal...

Ngày tải lên: 19/02/2014, 16:20

... mechanism of antitumour action of BS-RNase is based on the ability of the protein to resist the neutralizing action of the cytosolic RNase inhibitor, a resistance due to the dimeric structure of the enzyme. ... indicate that the cell sulfhydryls responsible for the exchange with the protein disulfides are located in the plasma membrane. Furthermore, they show that, as proposed in the hypothesis above, the RNase ... hypothesize that the cytotoxic activity of the latter monomers was due to the presence in these proteins of disulfide bonds, with their potential chemical instability. It is well known that in the...

Ngày tải lên: 20/02/2014, 11:20

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Ngày tải lên: 21/06/2014, 01:20

... minutes, which then switched to the opposite polarity for another 11.5 minutes. The device was designed to switch the di- rection of current flow halfway through the cycle. The resulting cycle ... (67). Inter- ruption of the overproduction of superoxide by the mitochondrial electron transport chain would nor- malize the pathways involved in the development of the oxidative stress ... role in the pathogenesis of both types of diabetes mellitus and cardiovascular diseases including hypertension. The low levels of antioxidants accompanied by raised levels of markers of free...

Ngày tải lên: 26/10/2012, 09:39

Ngày tải lên: 07/06/2013, 01:26

... analyzed the data about the Dien Bien - Lai Chau fault zone activities, the geological structure of the basin, as well as the theory of basin-forming regime to figure out the mechanism of formation ... along the long axis of the basin. The rock of the east side has been broken much more than that of the west side. - The cover composed of olivine basalt and loose sediments: + The Late Neogene ... started. On the west side of the basement, the subsidence may take place so quick that the basement slope is steeper and the bed rock is more stable. In turn, on the other side the bedrock...

Ngày tải lên: 13/02/2014, 12:20

... deuteration of C2¢ of the epimerase product. The lack of deuteration of the C2¢ of DHMP is not due to the lack of deute- rons, because it has been shown previously that the 6-hydroxymethyl group of the ... set of control data was obtained in the absence of the protein. The data set obtained in the absence of the protein was then subtracted from the corresponding data set obtained in the presence of ... performed in the absence of the ligand. The control data set obtained in the absence of the ligand was subtrac- ted from the corresponding data set obtained in the pres- ence of the ligand. The K d values...

Ngày tải lên: 19/02/2014, 00:20

... is composed of residues 25–540. The overall structure of the model of IPU and the mutated residues in this study are shown in Fig. 3. To elucidate the mechanism of the substrate recognition of IPU, ... panose (data not shown). Prediction of the positions of amino acid residues whose substitutions resulted in the reduction of the IPU activity While the study of site-directed mutagenesis described above ... in the negatively numbered subsites. The anomeric configuration of products of both Dex49A and IPU are identical, as well. Does the substrate preference of the negatively numbered s ubsites of...

Ngày tải lên: 19/02/2014, 16:20

... oxidize them [19]. On the other hand, this fact does not represent proof of the presence of one or two oxidizing equivalents on the decay product of Cpd I. The EPR spectrum of a spin-trapped radical ... formulated a hypo- thesis that describes an integrated vision of the catalytic mechanism of both enzymes. The main points are: (a) a re-evaluation of the role of superoxide as a reductant in the catalytic ... MPO. They dealwith the the major importance of catalase activity in MPO with respect to LPO, the different sensitivity of the enzymes to Cpd III inactivation and the redox potential of the chemical intermediates....

Ngày tải lên: 20/02/2014, 02:21

... trees with the nt sequence of the open reading frame (ORF) of their cDNAs and the corresponding aa sequences, in Table 1. Summary of the purification of DNases I from the pancreases of three species of ... cloned the cDNA of each. A single amino acid (aa) substitution was confirmed to affect the thermal stabilities of vertebrate DNases I and, furthermore, one of the postulated mechanisms whereby thermal ... not. The same was true for these mutants of the rat and mouse DNase I (Fig. 3). These findings demonstrate that the nature of the amino acid at position 130 may generally and markedly affect the thermal...

Ngày tải lên: 20/02/2014, 23:20