Disease relevance of Neuberg ester

• Unlike fructose-6-phosphate 1-kinase from Escherichia coli, in the absence of P-enolpyruvate, B. stearothermophilus PFK exhibits a hyperbolic profile with respect to Fru-6-P concentration [1].
• Arg252 of fructose-6-phosphate 1-kinase (PFK) from Bacillus stearothermophilus has been proposed to be involved in the binding of the substrate Fru-6-P [1].
• As a result, augmented fructose-6-P cycling does not substantially contribute to increased hepatic oxygen consumption in hyperthyroidism [2].
• At constant pressure perfusion, after 5 min after ischemia, cortical levels of creatine-phosphate, adenosine triphosphate (ATR), glucose, glucose-6-phosphate, and fructose-6-phosphate were higher in emopamil-treated brains than in controls, although the levels of adenosine diphosphate (ADP) and adenosine monophosphate (AMP) were reduced [3].
• Inorganic pyrophosphate dependent D-fructose-6-phosphate 1-phosphotransferase from Propionibacterium freudenreichii was purified to apparent homogeneity by the criterion of silver staining on sodium dodecyl sulfate (SDS) gels [4].

Psychiatry related information on Neuberg ester

• The availability of glutamine, and the activity of glutamine synthetase may control fructose-6-phosphate metabolism, and the increased ratio of fructose-1,6-diphosphatase to glutamine synthetase in Huntington's disease may explain the accumulation of glycogen, and the reduction in ganglioside levels reported in this state [5].
• The enzyme is clearly inhibited by ATP concentrations higher than 0.75 mM. pH increases maximum velocity and affinity of the enzyme towards fructose-6-phosphate and decreases the cooperative behavior of the enzyme [6].

High impact information on Neuberg ester

• We have discovered that the lipid-soluble thiamine derivative benfotiamine can inhibit these three pathways, as well as hyperglycemia-associated NF-kappaB activation, by activating the pentose phosphate pathway enzyme transketolase, which converts glyceraldehyde-3-phosphate and fructose-6-phosphate into pentose-5-phosphates and other sugars [7].
• We have cloned the gene for pig muscle phosphohexose isomerase (PHI) (EC 5.3.1.9) which catalyses the conversion of glucose-6-phosphate to fructose-6-phosphate, an obligatory step in glycolysis, and determined its amino-acid sequence [8].
• In conclusion, our results support the hypothesis that increased FFA availability induces skeletal muscle insulin resistance by increasing the flux of fructose-6-phosphate into the hexosamine pathway [9].
• Enzymatic analysis showed that the enzyme susceptible to the cancerous body fluids was D-fructose-6-phosphate 1-phosphotransferase (PFK), the rate-limiting key enzyme in the glycolysis pathway [10].
• The specific activity of L-glutamine: D-fructose-6-phosphate aminotransferase was measured in the oxyntic gland mucosa and liver of fasted, male rats after immobilization in a cold environment [11].

Chemical compound and disease context of Neuberg ester

• The mechanisms of L-glutamine hydrolysis, ammonia transfer and fructose-6P conversion into D-glucosamine-6P are analyzed with the E. coli enzyme in light of recent X-ray structures [12].
• The kinetics of the reverse reaction catalyzed by Escherichia coli phosphofructokinase, i.e., the synthesis of ATP and fructose-6-phosphate from ADP and fructose-1,6-bisphosphate, have been studied at different pH values, from pH 6 to pH 9 [13].
• L-Sorbose degradation in Klebsiella pneumoniae was shown to follow the pathway L-sorbose leads to L-sorbose-1-phosphate leads to D-glucitol-6-phosphate leads to D-fructose-6-phosphate [14].
• The presence of fructose-6-phosphate phosphoketolase, a key enzyme of bifidobacterial hexose metabolism, indicated the strains were members of the genus Bifidobacterium but they did not correspond to any of the recognized species of this genus on the basis of biochemical profiles and whole-cell protein analyses [15].
• Inorganic pyrophosphate: fructose-6-phosphate 1-phosphotransferase of the potato tuber is related to the major ATP-dependent phosphofructokinase of E. coli [16].

Biological context of Neuberg ester

• The active site lies in the central domain, contains a single essential zinc atom, and forms a deep, open cavity of suitable dimensions to contain M6P or F6P The central domain is flanked by a helical domain on one side and a jelly-roll like domain on the other [17].
• We have shown previously that bovine heart fructose-6-phosphate 2-kinase/fructose-2,6-bisphosphatase (EC 2.7.1.105/3.1.3.46) is phosphorylated by cAMP-dependent protein kinase and protein kinase C; phosphorylation results in activation of kinase [18].
• We isolated and sequenced two overlapping cDNA fragments, which together could encode the complete amino acid sequence of bovine heart fructose-6-phosphate 2-kinase/fructose-2,6-bisphosphatase, a protein of 530 amino acids, with a calculated molecular weight of 60,679 [18].
• Both native and phosphofructose-6-P,2-kinase show sigmoidal kinetics with respect to fructose-6-P with an apparent K0.5 of 15 microM and 50 microM, respectively [19].
• The Kobs of fructose-1,6-P2 hydrolysis, sigma fructose-1,6-P2 equilibrium sigma fructose-6-P + sigma Pi, was found to vary with free [Mg2+], being 272 M at free [Mg2+] = 0 and 174 M at free [Mg2+] = 0.89 x 10(-3) M [20].

Anatomical context of Neuberg ester

• The fructose-6-P saturation curve was sigmoid at all ATP levels tested [21].
• Regulation of insulin-stimulated glycogen synthase activity by overexpression of glutamine: fructose-6-phosphate amidotransferase in rat-1 fibroblasts [22].
• We report here that members of the tyrphostin family inhibit the GTPase activity of transducin and the enzymatic activities of other GTP-utilizing proteins in retinal rod outer segments, such as guanylyl cyclase or fructose-6-phosphate kinase [23].
• Significance of the amino terminus of rat testis fructose-6-phosphate, 2-kinase:fructose-2,6-bisphosphatase [24].
• In addition, Mu50 had enhanced glutamine synthetase and L-glutamine D-fructose-6-phosphate aminotransferase activities, which are involved in the cell-wall peptidoglycan synthesis pathway [25].

Associations of Neuberg ester with other chemical compounds

• Phosphomannose isomerase (PMI) catalyses the reversible isomerization of fructose-6-phosphate (F6P) and mannose-6-phosphate (M6P) [17].
• These two perturbations of the ATP-Thr-125 interaction lead to the suppression of both the allosteric inhibition by phosphoenolpyruvate and the cooperativity of fructose-6-phosphate saturation, as if replacing the neutral oxygen of ATP by sulfur or removing the methyl group of Thr-125 had "locked" phosphofructokinase in its active conformation [26].
• Glucosamine-6-phosphate deaminase (GNPDA) catalyzes the conversion of glucosamine-6-phosphate to fructose-6-phosphate, a reaction that under physiological conditions proceeds to the formation of fructose-6-phosphate [27].
• Acid treatment of both the synthetic and the natural product destroys the biological activity and yields 1 mol each of fructose-6-P and Pi; alkaline phosphatase treatment of the compound followed with acid hydrolysis yields fructose [28].
• Glu327 was not a substrate or product binding site determinant since the Km for fructose-2,6-bisphosphate and Ki for fructose-6-phosphate of the mutants were not appreciably changed [29].

Gene context of Neuberg ester

• The properties of pfk1 mutants suggest that yeast has an alternative mechanism for the aerobic metabolism of fructose-6-P, presumably through the recently reported particulate P-fructokinase (Lobo, Z., and Maitra, P. K. (1982) FEBS Lett. 137, 279-282) [30].
• The concentrations of adenine nucleotides, glucose-6-phosphate, and fructose-6-phosphate are comparable in the wild type and the hxk2 mutant [31].
• A truly bifunctional enzyme, 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (6PFK2/FBP2), with two active sites synthesizes F26P(2) from fructose-6-phosphate (F6P) and ATP or degrades F26P(2) to F6P and P(i) [32].
• A novel variant of glutamine: fructose-6-phosphate amidotransferase-1 (GFAT1) mRNA is selectively expressed in striated muscle [33].
• The N-half of the liver phosphofructokinase has conserved substrate binding sites for ATP and fructose-6-P [34].

Analytical, diagnostic and therapeutic context of Neuberg ester

• Site-directed mutagenesis in Bacillus stearothermophilus fructose-6-phosphate 1-kinase. Mutation at the substrate-binding site affects allosteric behavior [1].
• The effect of the binding of fructose-6-P or MgATP2- on the polarization fluorescence of the emission of Trp88 in Pfk-2 indicates changes in the local mobility of the Trp88 in both enzyme complexes [35].
• The inactivation could be reversed by addition of fru-6-P, but not ATP, to the incubating media at 37.5 degrees C. Lens organ culture studies showed that the depletion of lenticular ATP seemed to precipitate the loss of PFK [36].
• Further, formation of [32P]ATP was observed after microinjection of 32P-labelled glucose-6-P, fructose-6-P or fructose-1,6-bis-P, either in the presence or absence of 0.1 mM cyanide [37].
• A total of 46 isolates from six neonates were confirmed to be Bifidobacterium species based on a combination of the fructose-6-phosphate phosphoketolase assay, RAPD [random(ly) amplified polymorphic DNA] PCR, pulsed-field gel electrophoresis (PFGE), and partial 16S ribosomal DNA sequencing [38].

References