scholarly journals The Common Feature of Leukemia-Associated IDH1 and IDH2 Mutations Is a Neomorphic Enzyme Activity Converting α-Ketoglutarate to 2-Hydroxyglutarate

Cancer Cell ◽  
2010 ◽  
Vol 17 (3) ◽  
pp. 225-234 ◽  
Author(s):  
Patrick S. Ward ◽  
Jay Patel ◽  
David R. Wise ◽  
Omar Abdel-Wahab ◽  
Bryson D. Bennett ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
The Common ◽  
Idh1 And Idh2 Mutations

scholarly journals Registered report: The common feature of leukemia-associated IDH1 and IDH2 mutations is a neomorphic enzyme activity converting alpha-ketoglutarate to 2-hydroxyglutarate

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Oliver Fiehn ◽  
Megan Reed Showalter ◽  
Christine E Schaner-Tooley ◽  
Keyword(s):  
Enzyme Activity ◽  
Myeloid Leukemia ◽  
Cancer Biology ◽  
Open Science ◽  
Wild Type ◽  
High Profile ◽  
Isocitrate Dehydrogenase 2 ◽  
The Common ◽  
Idh1 And Idh2 Mutations ◽  
Acute Myeloid

The Reproducibility Project: Cancer Biology seeks to address growing concerns about reproducibility in scientific research by conducting replications of selected experiments from a number of high-profile papers in the field of cancer biology. The papers, which were published between 2010 and 2012, were selected on the basis of citations and Altmetric scores (<xref ref-type="bibr" rid="bib3">Errington et al., 2014</xref>). This Registered Report describes the proposed replication plan of key experiments from “The common feature of leukemia-associated IDH1 and IDH2 mutations is a neomorphic enzyme activity converting alpha-ketoglutarate to 2-hydroxyglutarate” by Ward and colleagues, published in Cancer Cell in 2010 (<xref ref-type="bibr" rid="bib16">Ward et al., 2010</xref>). The experiments that will be replicated are those reported in Figures 2, 3 and 5. Ward and colleagues demonstrate the mutations in isocitrate dehydrogenase 2 (IDH2), commonly found in acute myeloid leukemia (AML), abrogate the enzyme’s wild-type activity and confer to the mutant neomorphic activity that produces the oncometabolite 2-hydroxyglutarate (2-HG) (Figures 2 and 3). They then show that elevated levels of 2-HG are correlated with mutations in IDH1 and IDH2 in AML patient samples (Figure 5). The Reproducibility Project: Cancer Biology is a collaboration between the Center for Open Science and Science Exchange and the results of the replications will be published by eLife.

scholarly journals Replication Study: The common feature of leukemia-associated IDH1 and IDH2 mutations is a neomorphic enzyme activity converting alpha-ketoglutarate to 2-hydroxyglutarate

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Megan Reed Showalter ◽  
Jason Hatakeyama ◽  
Tomas Cajka ◽  
Kacey VanderVorst ◽  
Kermit L Carraway ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Vector Control ◽  
Cancer Biology ◽  
Original Study ◽  
Idh Mutation ◽  
Wild Type ◽  
The Common ◽  
Idh1 And Idh2 Mutations ◽  
Mutant Idh1 ◽  
Meta Analyses

In 2016, as part of the Reproducibility Project: Cancer Biology, we published a Registered Report (<xref ref-type="bibr" rid="bib14">Fiehn et al., 2016</xref>), that described how we intended to replicate selected experiments from the paper "The common feature of leukemia-associated IDH1 and IDH2 mutations is a neomorphic enzyme activity converting alpha-ketoglutarate to 2-hydroxyglutarate" (Ward et al., 2010). Here, we report the results of those experiments. We found that cells expressing R172K mutant IDH2 did not display isocitrate-dependent NADPH production above vector control levels, in contrast to the increased production observed with wild-type IDH2. Conversely, expression of R172K mutant IDH2 resulted in increased alpha-ketoglutarate-dependent consumption of NADPH compared to wild-type IDH2 or vector control. These results are similar to those reported in the original study (Figure 2; Ward et al., 2010). Further, expression of R172K mutant IDH2 resulted in increased 2HG levels within cells compared to the background levels observed in wild-type IDH2 and vector control, similar to the original study (Figure 3D; Ward et al., 2010). In primary human AML samples, the 2HG levels observed in samples with mutant IDH1 or IDH2 status were higher than those observed in samples without an IDH mutation, similar to what was observed in the original study (Figure 5C; Ward et al., 2010). Finally, we report meta-analyses for each result.

scholarly journals Induction of chalcone synthase and phenylalanine ammonia-lyase by salicylic acid and Colletotrichum lindemuthianum in common bean

2003 ◽  
Vol 15 (3) ◽  
pp. 129-134 ◽  
Author(s):  
Ângela Diniz Campos ◽  
Alfredo Gui Ferreira ◽  
Magdolna Maria Vozári Hampe ◽  
Irajá Ferreira Antunes ◽  
Nely Brancão ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Salicylic Acid ◽  
Common Bean ◽  
Phenylalanine Ammonia Lyase ◽  
Chalcone Synthase ◽  
Colletotrichum Lindemuthianum ◽  
Water Control ◽  
Leaf Extracts ◽  
The Common ◽  
Two Stages

The activities of the enzymes chalcone synthase (CHS) and phenylalanine ammonia-lyase (PAL) were measured in leaf extracts obtained from four cultivars of the common bean (AB 136, Rio Tibagi, Carioca and Macanudo). Two stages of plant development were examined: plantlets (V2) and the onset of blooming (R6). Initially, the plants were either treated with salicylic acid or inoculated with the delta race of Colletotrichum lindemuthianum (inductive fungus) and after three days they were evaluated for enzyme activity. Afterwards, all plants were inoculated (challenged) with the virulent pathotype 33/95 of C. lindemuthianum except for the water control. Five days later, the activities of PAL and CHS were evaluated. There were significant changes in the activities of both enzymes three days after treatment with salicylic acid or inductive fungus when compared to the control. Five days after inoculation with with the virulent pathotype 33/95 of C. lindemuthianum CHS activity in the Macanudo was similar to control plants that were not treated with salicylic acid or the inductive fungus but inoculated with 33/95 C. lindemuthianum. The increase in enzyme activity after challenge with 33/95 C. lindemuthianum was greatest for the salicylic acid treatment in the cultivar AB 136, followed by Rio Tibagi and Carioca.

Application of three-phase partitioning to the purification and characterization of polyphenol oxidase from antioxidant rosemary (Rosmarinus officinalis L.)

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Yonca Yuzugullu Karakus ◽  
Busra Kahveci ◽  
Arda Acemi ◽  
Gulden Kocak
Keyword(s):  
Enzyme Activity ◽  
Polyphenol Oxidase ◽  
Cetyltrimethylammonium Bromide ◽  
Rosmarinus Officinalis ◽  
Phase Partitioning ◽  
Three Phase ◽  
Diammonium Salt ◽  
The Common ◽  
Rosmarinus Officinalis L

AbstractPolyphenol oxidase (PPO) has been purified from the rosemary plant (Rosmarinus officinalis L.) through three-phase partitioning (TPP) and has been biochemically characterized. The optimized TPP consisted of 50% (w/v) ammonium sulfate and equal volumes of crude extract and tert-butanol prepared at pH 6.5 and room temperature. Using this system, PPO was purified 14-fold, with 230% recovery of activity from the middle phase. The partitioned enzyme had a molecular mass of 53 kDa. The highest enzyme activity was detected at 30 °C and pH 7.0 against catechol. In substrate specificity tests, the enzyme displayed activity towards catechol, 4-methylcatechol, caffeic acid, hydroquinone, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), pyrogallol, syringaldezine, and 3,4-dihydroxy-L-phenylalanine but no activity towards L-tyrosine. The enzyme was inhibited by the common PPO inhibitors; salicylhydroxamic acid (SHAM), cetyltrimethylammonium bromide (CTAB), polyvinylpyrrolidone (PVP), and the organic solvent dimethyl sulfoxide (DMSO). Enzyme activity increased in the presence of the organic solvents acetone, ethanol, and methanol.

scholarly journals Fusion of a functional glutaredoxin to the radical-generating subunit of ribonucleotide reductase

2018 ◽  
Author(s):  
Inna Rozman Grinberg ◽  
Daniel Lundin ◽  
Margareta Sahlin ◽  
Mikael Crona ◽  
Gustav Berggren ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Fusion Protein ◽  
Ribonucleotide Reductase ◽  
Reaction Mechanisms ◽  
Catalytic Subunit ◽  
Class I ◽  
Terminal Domain ◽  
The Common

AbstractClass I ribonucleotide reductase (RNR) consists of a catalytic subunit (NrdA) and a radical-generating subunit (NrdB) that together catalyse reduction of the four ribonucleotides to their corresponding deoxyribonucleotides.Facklamia ignavaNrdB is an unprecedented fusion protein with N-terminal add-ons of a glutaredoxin (Grx) domain followed by an ATP-cone. Grx, which in general is encoded elsewhere in the genome than is the RNR operon, is a known physiological reductant of RNRs. Here we show that the fused Grx domain functions as an efficient reductant of theF. ignavaclass I RNR via the common dithiol mechanism and interestingly also via a monothiol mechanism, although less efficiently. A Grx that utilizes either or of these two reaction mechanisms has to our knowledge not been observed with a native substrate before. The ATP-cone, which is commonly found as an N-terminal domain of the catalytic subunit of RNRs, is an allosteric on/off switch that promotes dNDP reduction in presence of ATP and inhibits the enzyme activity in presence of dATP. Here we show that dATP bound to the ATP-cone ofF. ignavaNrdB promotes formation of tetramers that are unable to form enzymatically competent complexes withF. ignavaNrdA. The ATP-cone binds two molecules of dATP, but only one molecule of the activating nucleotide ATP.F. ignavaNrdB contains the recently identified radical factor Mn2III/IV. We show that NrdA from the firmicuteF. ignavacan form a catalytically competent RNR with the Mn2III/IV-containing NrdB from the flavobacteriumLeeuwenhoekiella blandensis.

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