Search results for "Cyst"
showing 10 items of 1960 documents
Plasma homocysteine levels in patients with chronic renal failure.
2004
Comparison of two assays for serum homocysteine measurement
2008
Atherothrombotic Stroke: Plasmatic Modification Of Homocysteine and Other Thiols
2004
Practices in research, surveillance and control of neglected tropical diseases by One Health approaches: A survey targeting scientists from French-sp…
2021
One health (OH) approaches have increasingly been used in the last decade in the fight against zoonotic neglected tropical diseases (NTDs). However, descriptions of such collaborations between the human, animal and environmental health sectors are still limited for French-speaking tropical countries. The objective of the current survey was to explore the diversity of OH experiences applied to research, surveillance and control of NTDs by scientists from French-speaking countries, and discuss their constraints and benefits. Six zoonotic NTDs were targeted: echinococcoses, trypanosomiases, leishmaniases, rabies, Taenia solium cysticercosis and leptospiroses. Invitations to fill in an online q…
Mechanism of sulfur transfer across protein-protein interfaces: The cysteine desulfurase model system
2016
CsdA cysteine desulfurase (the sulfur donor) and the CsdE sulfur acceptor are involved in biological sulfur trafficking and in iron-sulfur cluster assembly in the model bacterium Escherichia coli. CsdA and CsdE form a stable complex through a polar interface that includes CsdA Cys328 and CsdE Cys61, the two residues known to be involved in the sulfur transfer reaction. Although mechanisms for the transfer of a sulfur moiety across protein-protein interfaces have been proposed based on the IscS-IscU and IscS-TusA structures, the flexibility of the catalytic cysteine loops involved has precluded a high resolution view of the active-site geometry and chemical environment for sulfur transfer. H…
Properties and significance of apoFNR as a second form of air-inactivated [4Fe-4S]·FNR of Escherichia coli
2005
The active form of the oxygen sensor fumarate nitrate reductase regulator (FNR) of Escherichia coli contains a [4Fe-4S] cluster which is converted to a [2Fe-2S] cluster after reaction with air, resulting in inactivation of FNR. Reaction of reconstituted [4Fe-4S].FNR with air resulted within 5 min in conversion to apoFNR. The rate was comparable to the rate known for [4Fe-4S].FNR/[2Fe-2S].FNR cluster conversion, suggesting that apoFNR is a product of [2Fe-2S].FNR decomposition and a final form of air-inactivated FNR in vitro. Formation of apoFNR and the redox state of the cysteinyl residues were determined in vitro by alkylation. FNR contains five cysteinyl residues, four of which (Cys20, Cy…
Redox modulation of Rubisco conformation and activity through its cysteine residues
2008
Treatment of purified Rubisco with agents that specifically oxidize cysteine-thiol groups causes catalytic inactivation and increased proteolytic sensitivity of the enzyme. It has been suggested that these redox properties may sustain a mechanism of regulating Rubisco activity and turnover during senescence or stress. Current research efforts are addressing the structural basis of the redox modulation of Rubisco and the identification of critical cysteines. Redox shifts result in Rubisco conformational changes as revealed by the alteration of its proteolytic fragmentation pattern upon oxidation. In particular, the augmented susceptibility of Rubisco to proteases is due to increased exposure…
The fnr Gene of Bacillus licheniformis and the Cysteine Ligands of the C-Terminal FeS Cluster
1998
Many of the O2-responsive gene regulators of bacteria are members of the fumarate nitrate reductase-cyclic AMP receptor protein family of transcriptional regulators (12, 13, 15, 17) with predicted structures similar to those of the cyclic AMP receptor protein (11). The Fnr (stands for fumarate nitrate reductase regulator) protein from Escherichia coli (FnrEc) controls the expression of a variety of genes, mainly of anaerobic respiration and metabolism (5, 13). It contains a N-terminal cluster of three essential cysteine residues which are supposed to bind together with Cys122 a [4Fe 4S]2+ cluster which is required for O2 sensing (4, 7, 8, 10, 16). A wide variety of gram-negative bacteria co…
Synovial giant cells in rheumatoid arthritis: Expression of cystatin C, but not of cathepsin B
2000
This study was designed to investigate the expression of the matrix degrading proteinase cathepsin B and its endogenous inhibitor cystatin C in rheumatoid arthritis (RA) with special regard to multinucleated synovial giant cells (SGC). We applied an immunohistochemical double-labeling technique. SGC strongly expressed cystatin C and CD68, but were negative for cathepsin B. This staining pattern occurred in osteoclasts as well. Our findings support the idea that in RA matrix destruction by cathepsin B is not mediated by SGC or osteoclasts, but by mononuclear synoviocytes.
Role of glutathione in the formation of the active form of the oxygen sensor FNR ([4Fe-4S]·FNR) and in the control of FNR function
2000
The oxygen sensor regulator FNR (fumarate nitrate reductase regulator) of Escherichia coli is known to be inactivated by O2 as the result of conversion of a [4Fe-4S] cluster of the protein into a [2Fe-2S] cluster. Further incubation with O2 causes loss of the [2Fe-2S] cluster and production of apoFNR. The reactions involved in cluster assembly and reductive activation of apoFNR isolated under anaerobic or aerobic conditions were studied in vivo and in vitro. In a gshA mutant of E. coli that was completely devoid of glutathione, the O2 tension for the regulatory switch for FNR-dependent gene regulation was decreased by a factor of 4–5 compared with the wild-type, suggesting a role for glutat…