Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.1.1.41 (isocitrate dehydrogenase)
 3,101 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chaperonin 60 and chaperonin 10 (GroEL and GroES homologues, respectively) have been isolated from extracts of the anaerobic thermophile Thermoanaerobacter brockii. A simple and rapid purification for chaperonin 60 made use of hydrophobic and anion-exchange chromatographies, and could be readily scaled up; approximately 2 mg pure chaperonin 60 was obtained/g cells. In contrast with all other prokaryotic chaperonin 60 proteins that have been studied, which are tetradecamers, including those from Thermus sp., the T. brockii protein is a heptamer, and as isolated was not in association with chaperonin 10. The preparation is readily crystallized using 2-propanol or poly(ethylene glycol) with MgCl2. The N-terminal amino acid sequence of this preparation is similar to other thermophilic chaperonin 60 proteins. Chaperonin 10 was purified from the flow-through of the first hydrophobic column (which bound chaperonin 60) using a more hydrophobic adsorbent to remove contaminating proteins, followed by anion-exchange chromatography. Chaperonin 10 was obtained with a yield of approximately 10% that of chaperonin 60. The subunit molecular mass of chaperonin 10 determined by electrospray mass spectrometry is 10254 +/- 0.4 Da, which is very similar to the molecular mass of Escherichia coli GroES. Similarly, the subunit size of chaperonin 60 determined by mass spectrometry is very similar to that of GroEL, at 57949 +/- 10 Da. T. brockii chaperonin 60 has an ATPase activity that is suppressed by chaperonin 10, and the two proteins together are active in protein-folding assays. Mitochondrial malate dehydrogenase was successfully refolded at 37 degrees C after denaturation in guanidine hydrochloride, using T. brockii chaperonin 60 and chaperonin 10, or chaperonin 60 and E. coli GroES. The denatured enzyme was protected from aggregation by association with chaperonin 60. Guanidine-hydrochloride-denatured preparations of isocitrate dehydrogenase and secondary alcohol dehydrogenase isolated from T. brockii were also refolded at 60-65 degrees C. In each case, refolding required chaperonin 60, chaperonin 10 and ATP, giving up to 80% regeneration of control activity.
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PMID:Purification and characterization of chaperonin 60 and chaperonin 10 from the anaerobic thermophile Thermoanaerobacter brockii. 791 71

We previously isolated and identified Enterobacter sp. NKNU02 as a methyl tert-butyl ether (MTBE)-degrading bacterial strain from gasoline-contaminated water. In this study, tert-butyl alcohol, acetic acid, 2-propanol, and propenoic acid were detected using gas chromatography/mass spectrometry when MTBE was degraded by rest cells of Enterobacter sp. NKNU02 cells. We also found that biodegradation of MTBE was decreased, but not totally inhibited in mixtures of benzene, toluene, ethylbenzene and xylene. The effects of MTBE on the biology of Enterobacter sp. NKNU02 were elucidated using 2D proteomic analysis. The cytoplasmic proteins isolated from these MTBE-treated and -untreated cells were carried out for proteomic analysis. Results showed that there were 6 differential protein spots and 8 differential protein spots, respectively, as compared to their corresponding control (without MTBE addition), at the indicated incubation times when 40% and 60% of 100 mg/L of MTBE had been removed, Among these proteins, nine were successfully identified with matrix-assisted laser desorption ionization-time of flight-mass spectrometry. Proteins identified included extracellular solute-binding protein, periplasmic-binding protein ytfQ, cationic amino acid ABC transporter, isocitrate dehydrogenase, cysteine synthase A, alkyl hydroperoxide reductase (AhpC), transaldolase, and alcohol dehydrogenase. Based on these differential proteins, we discuss the bacterial responses to MTBE at the molecular level.
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PMID:Biodegradation of methyl tert-butyl ether (MTBE) by Enterobacter sp. NKNU02. 2122 85