• The purpose of these studies is to probe the cause of inactivation of purified CDO and to determine how the 3-His facial triad and Cys-Tyr crosslink affect the catalytic properties of the enzyme. (auburn.edu)
  • To determine if inactivation of CDO occurring during purification is the result of an inability of the enzyme to protect its metal center from oxidation, EPR spectra and activity measurements were made of CDO expressed in cell lysate and following purification. (auburn.edu)
  • The combined sensitivity of CDO to inactivation by oxidation of the metal center and crosslink formation may be linked physiologically and represent a redox sensitive regulation of CDO activity. (auburn.edu)
  • Catechol dioxygenases are further classified as being "extradiol" or "intradiol," and this distinction is based on mechanistic differences in the reactions (figures 1 & 2). (wikipedia.org)
  • Here, we review the recent findings on the microbial communities that are involved in the oxidation of inorganic sulfur compounds and address how the two elements of sulfur and carbon are interlinked and influence the ecology and biogeochemistry in the ocean. (springer.com)
  • Though a body of evidence indicated that NO elicits up-regulation of COX activity, 13-16 a large number of reports support the idea that NO inactivates COX 17-19 or has little effect on enzyme activity under certain conditions. (rsc.org)
  • 22 Recently, we found that the first irreversible hydrogen transfer step in COX-2 catalysis altered along with oxygen variations, 23 suggesting that the oxygen concentration has a huge impact on enzyme activity. (rsc.org)
  • The most common methods of enzyme activity measurement involve monitoring absorbance or fluorescence of a solution of enzyme and substrate as a function of time. (olisweb.com)
  • The solution viscosity, deuterium kinetic isotope effect (KIE), and oxygen-18 KIE experiments further demonstrate that NO activates COX-2 by altering the protein conformation to stimulate substrate association/product release and by accelerating the rate of hydrogen abstraction from AA by catalytic tyrosine radicals. (rsc.org)
  • In line with the most recent reports, it was emphasized that sulfane sulfur-containing compounds (mainly hydrogen persulfides and polysulfides) are real and better mediators of S-sulfhydration-based signalling than H 2 S. We also overviewed proteins participating in the formation and transport of RSS and in mitochondrial H 2 S oxidation. (bioscirep.org)
  • This hypothesis includes also another class of RSS, i.e. the products of cysteine transformations: hydrogen sulfide (H 2 S) and sulfane sulfur-containing compounds. (bioscirep.org)
  • The authors observed that despite the high sequence similarity, MpNEP1 and MpNEP2 present different structural features, and MpNEP2 activity was resistant to high temperatures. (biomedcentral.com)
  • In the first few sections, we will cover the structure and catalytic cycles of typical halogenases and haloperoxidases in nature, while in the second part of this review, recent studies from our group on nonheme iron halogenases and hydroxylases are discussed. (mdpi.com)
  • Of the kinetic models proposed for COX catalysis, the "branch-chain" model is generally favored because it reveals the independent peroxidase and dioxygenase cycles ( Scheme 1 ). (rsc.org)
  • Uncovering human METTL12 as a mitochondrial methyltransferase that modulates citrate synthase activity through metabolite-sensitive lysine methylation. (uio.no)
  • Human METTL20 is a mitochondrial lysine methyltransferase that targets the β subunit of electron transfer flavoprotein (ETFβ) and modulates its activity. (uio.no)
  • Unlike Warburg's proposal, tumor cell mitochondria not only retain their functionality, but are also instrumental for integrating a variety of signals and adjusting the metabolic activity of the cell to such a demanding and stressful situation ( 4 ) (Figure 1 ). (frontiersin.org)
  • OXPHOS activity is down-regulated, but not abolished, in many tumor cell types. (frontiersin.org)
  • LO-mediated products elicit diverse biological activities needed for neoplastic cell growth, influencing growth factor and transcription factor activation, oncogene induction, stimulation of tumor cell adhesion, and regulation of apoptotic cell death. (aacrjournals.org)
  • Agents that block LO-catalyzed activity may be effective in preventing cancer by interfering with signaling events needed for tumor growth. (aacrjournals.org)
  • They contain characteristic lanthionine (Lan) or methyllanthionine (MeLan) structures that contribute to their diverse biological activities. (usda.gov)
  • To create mirror-image active sites, nature can change the location of the binding site and/or the location of key catalytic groups. (docme.ru)
  • These metabolic changes down-regulate the TCA cycle, both because induction of PPP and of anabolic pathways that branch from glycolysis limit pyruvate availability, and because a low OXPHOS activity inhibits the formation of NAD + and FAD required for TCA cycle dehydrogenases. (frontiersin.org)
  • The cysteine thiolate-co-ordinated ferric P450 typically has its major (Soret band) absorbance maximum at ∼418 nm [ 4 ]. (biochemsoctrans.org)
  • The purpose of these studies is to probe the cause of inactivation of purified CDO and to determine how the 3-His facial triad and Cys-Tyr crosslink affect the catalytic properties of the enzyme. (auburn.edu)
  • Recently, it was discovered that in the heart myoglobin represents dioxygenase and nitrite reductase properties. (biologists.org)
  • Activity was recoverable by the addition of L-ascorbate to assays and this corresponded to reduction of the metal center as observed by EPR. (auburn.edu)
  • In addition, we demonstrated that the dioxygenase activity of COX-2 can be analyzed independently of peroxidase activity by adding sufficient phenol, which acts as a sacrificed reductant, 22,23 at a concentration of up to 2.5 mM. (rsc.org)
  • To determine if inactivation of CDO occurring during purification is the result of an inability of the enzyme to protect its metal center from oxidation, EPR spectra and activity measurements were made of CDO expressed in cell lysate and following purification. (auburn.edu)
  • The majority of dioxygenases fully incorporate dioxygen into a single substrate, and a variety of cofactor schemes are utilized to achieve this. (wikipedia.org)
  • Moracci, M. Introducing Transgalactosylation Activity Into A Family 42 $\upbeta$-Galactosidase . (ubc.ca)
  • 2001). Dissecting the Electrostatic Interactions and pH-Dependent Activity of a Family II Glycosidase. (olisweb.com)