Tài liệu Báo cáo Y học: Inactivation of the 2-oxo acid dehydrogenase complexes upon generation of intrinsic radical species pptx

... that the thiyl radical of the complex-bound dihydrolipoate induces the inactivation by 1e – oxidation of the 2-oxo acid dehydrogenase catalytic intermediate. A pro- duct of this oxidation, the ... pool. Keywords: dihydrolipoate; 2-oxo acid dehydrogenase com- plex; reactive oxygen species; thiyl radical; thioredoxin. The 2-oxo acid dehydrogenase compl...

Ngày tải lên: 21/02/2014, 01:21

... methyl groups are always introduced, one slowly by Dnmt3a or by de novo methylation catalyzed by Dnmt1 and the second one very fast. Therefore, this effect can only double the rate of DNA methylation, ... novo methylation of DNA [15]. Interestingly, the de novo activity of Dnmt1 is stimulated by binding of methylated DNA to an allosteric site located in the N-terminal domain...

Ngày tải lên: 21/02/2014, 01:21

... orientation of a metal-bound hydroxide for optimal attack on the guanidinium carbon of agmatine. Thus, the disruption of this hydrogen bond is the likely cause of the greately decreased catalytic efficiency ... we conclude that the lower activity of the mutant may be ascribed to the loss of an acceptor hydrogen bond to a metal-bound hydroxide, as a consequence of rep...

Ngày tải lên: 21/02/2014, 01:21

... as the standard. RESULTS Induction of citral lyase Initially, the reproducibility of the results was hindered by variations in the citral lyase activity of the P. digitatum spores. Remarkably, ... induction. Stability of citral lyase activity The activity and stability of citral lyase was dramatically affected by the addition of 20% (v/v) glycerol and 1 m M EDTA. Whe...

Ngày tải lên: 21/02/2014, 01:21

... 2C-methyl- D-erythritol 4-phosphate can be converted into a cyclic diphosphate by the consecutive action of 4-diphosphocytidyl-2C-methyl- D- erythritol synthase, 4-diphosphocytidyl-2C-methyl- D-erythritol kinase ... exchange (2% of the isomerization rate) of the methyl group of IPP and the (Z)-methyl group of DMAPP, and an even slower exchange (0.5% of the isomerization...

Ngày tải lên: 22/02/2014, 07:20

... could be the limiting step in BLXI inactivation. Higher E a values of inactivation for the Co 2þ – enzyme and the Mn 2þ –enzyme reflect the higher thermal energy that these metal–enzyme complexes ... than for xylose, and the relative effectiveness of the three metals was the same. Occupancy rate of the M2 site necessary for activity on glucose may be higher than that...

Ngày tải lên: 22/02/2014, 07:20

... complex of the respiratory chains of mitochondria and many bacteria [1–4]. It catalyzes the reduction of oxygen to water, coupling the free energy of this reaction to the generation of a proton gradient ... hypothetical second site have been made here for the bacterial enzyme by stripping subunits III and IV off the native complex, and by further destroying a large par...

Ngày tải lên: 22/02/2014, 07:20

... N-Methylphenylalanine is the N-terminal amino acid of pilins of most bacterial pathogens expressing type IV pili [7]. The synthesis of these N-methylated peptides is catalyzed by specific N-methyltransferases ... Accord- ingly, we named the enzyme N-methyl-l-amino acid dehydrogenase to distinguish it from the previously reported N-methylalanine dehydrogenase [17]. More- o...

Ngày tải lên: 19/02/2014, 16:20

... were recently introduced for the preparation of C-6 aldehyde derivatives of Glc [15]. The key step is the use of Collins reagent for the selective oxidation of the primary trimethyl- silyl ether of the ... stereoselective synthesis of enantiomerically pure mono- and di-O-hexadecyl-b- D -glucosylglycerol ethers by epoxidation of an allyl b- D -glucopyranoside asymmetr...

Ngày tải lên: 21/02/2014, 01:21

... used. RESULTS The enzymatic activity and molecular stability of the mutants The catalytic activity and the molecular stability of the mutants were assayed because a change in either of these parameters ... seen from their inactivation rates in the presence of equimolar amounts of trypsin (Table 2). The cleavage of the interdomain and autolysis loops To follow th...

Ngày tải lên: 22/02/2014, 07:20