Phosphofructokinase

The characterization of the gene encodingLeishmania donovaniphosphofructokinase (PFK) and the biochemical properties of the expressedenzyme are reported.L. donovani has a singlePFKgene copyperhaploidgenome that encodes a polypeptide with a deducedmolecular mass of 53 988 and a pI of 9.26. The predicted amino acid sequence contains a C-terminal tripeptide that conforms to an established signal for glycosome targeting.

12p research12 23-04-2013 62 3   Download

We used parameter scanning to emulate changes to the limitingrate for steps inafittedmodel of glucose-derepressed yeast glycolysis. Three flux-control regimes were observed, two of which were under the dominant control of hexose transport, in accordance with various experimental studies andothermodel predictions.

11p research12 23-04-2013 42 2   Download

In Lactococcus lactisthe enzymes phosphofructokinase (PFK), pyruvate kinase (PK) and lactate dehydrogenase (LDH) are uniquely encoded in the las operon. We used metabolic control analysis to study the role of this organization. Earlier studies have shown that, at wild-type levels, LDH has no control over glycolysis and growth rate, but high negative control over formate production (C Jformate LDH ¼
1:3).

12p awards 06-04-2013 33 3   Download

This work concerns the cause of glycolytic oscillations in yeast. We analyse experimental data as well as models in two distinct cases: the relaxation-like oscillations seen in yeast extracts, and the sinusoidal Hopf oscillations seen in intact yeast cells. In the case of yeast extracts, we use flux-change plots and model analyses to establish that the oscillations are driven by on⁄off switching of phosphofructokinase.

13p awards 06-04-2013 36 5   Download

The synthesis of ATP in the human parasiteEntamoeba histolyticais car-ried out solely by the glycolytic pathway. Little kinetic and structural infor-mation is available for most of the pathway enzymes.

17p awards 06-04-2013 34 3   Download

Temperature effects on the kinetic properties of phosphofructokinase (PFK) purified from skeletal muscle of the golden-mantled ground squirrel, Spermophilus lateralis, were examined at 37
C and 5
C, values character-istic of body temperatures in euthermia vs. hibernation. The enzyme showed reduced sensitivity to all activators at 5
C, theKa values for AMP, ADP, NH4 + and F2,6P2 were 3–11-fold higher at 5
C than at 37
C. Inhibition by citrate was not affected whereas phosphoenolpyruvate, ATP and urea became more potent inhibitors at low temperature. ...

0p awards 05-04-2013 41 2   Download

Despite its importance in plant metabolism, no sequences of higher plant ATP-dependent phosphofructokinase (EC 2.7.1.11) are annotated in the databases. We have purified the enzyme from spinach leaves 309-fold to electrophoretic homogeneity. The purified enzyme was a homotetramer of 52 kDa subunits with a specific activity of 600 mUÆmg )1 and aKmvalue for ATP of 81 lm.

10p inspiron33 23-03-2013 47 5   Download

In several archaea of the Euryarchaeota, the glycolytic flux proceeds through a modified version of the Embden–Meyerhof pathway, where the phosphofructokinase and glucokinase enzymes use ADP as the phosphoryl donor. These enzymes are homologous to each other. In the hyperthermo-philic methanogenic archaeon

12p galaxyss3 07-03-2013 42 2   Download

The genome of the mesophilic Gram-negative bacteriumBurkholderia thai-landensis contains an open reading frame (i.e. theBth_I1158gene) that has been annotated as a putative ribokinase and PFK-B family member. Nota-bly, although the deduced amino acid sequence of the gene showed only 29% similarity to the recently identified nucleoside kinase from hyperthermophilic archaeaMethanocaldococcus jannaschii, 15 of 17 residues reportedly involved in the catalytic activity of M.

8p vinaphone15 28-02-2013 53 3   Download