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K Nissler

Publications and source records attributed to K Nissler.

At least 37 records · Page 2Linked to original sources
PubMed1984

Interaction of Cibacron blue F3G-A with yeast phosphofructokinase.

The binding of Cibacron blue F3G-A to yeast phosphofructokinase was investigated by means of ultracentrifugation. Four moles of Cibacron blue are tightly bound per subunit of phosphofructokinase (dissociation constant = 0.26 microM). This stoichiometry does not correspond to the stoichiometry of ATP binding to yeast phosphofructokinase (two moles of ATP per subunit). Moreover, 32 moles of the dye are bound per subunit of phosphofructokinase to a second class of binding sites with low affinity (dissociation constant = = 53 microM). The action of Cibacron blue on yeast phosphofructokinase cannot be explained completely in terms of its function as ATP analogue.

Adenosine Triphosphate↗
PubMed1984

Cooperation of fructose-2,6-bisphosphate and AMP in the activation of yeast phosphofructokinase.

Yeast phosphofructokinase is effectively activated by AMP and fructose-2,6-bisphosphate. Both effectors influence the sensitivity of the enzyme with respect to fructose-6-phosphate and increase the respective maximum activities. The dependence of phosphofructokinase activity on the concentration of fructose-2,6-bisphosphate was measured at different AMP concentrations and vice versa. By AMP the half activation constant for fructose-2,6-bisphosphate is decreased by one order of magnitude. The affinity to AMP is significantly increased by fructose-2,6-bisphosphate. AMP increases the maximum activity of the enzyme with respect to fructose-2,6-bisphosphate only slightly, while the maximum activity with respect to AMP is drastically increased by fructose-2,6-bisphosphate. The interaction of the two activators is most pronounced at low levels of fructose-6-phosphate and at high concentrations of ATP.

Adenosine Monophosphate↗
PubMed1984

Influence of inorganic phosphate on the kinetic properties of yeast phosphofructokinase.

Yeast phosphofructokinase is effectively activated by inorganic phosphate. In the absence of other allosteric stimulators, inorganic phosphate increases the maximum activity of the enzyme only. In the presence of the activators AMP and fructose 2,6-bisphosphate inorganic phosphate causes changes in the maximum activity and the enzyme affinity to fructose 6-phosphate. Inorganic phosphate augments the sensitivity of phosphofructokinase to the activators AMP and fructose 2,6-bisphosphate and increases the respective maximum activities. The extent of activation of the enzyme by inorganic phosphate prevails at low levels of fructose 6-phosphate and high ATP concentrations.

Adenosine Monophosphate↗
PubMed1983

Similarity of activation of yeast phosphofructokinase by AMP and fructose-2,6-bisphosphate.

Phosphofructokinase from yeast is effectively activated by AMP and fructose-2,6-bisphosphate by increasing the affinity of the enzyme to fructose-6-phosphate and the maximum activity toward this substrate. The enzyme is activated by AMP and fructose-2, 6-bisphosphate both at high and at low concentrations of ATP. The half maximum stimulation concentrations of AMP and fructose-2, 6-bisphosphate are about 200 microM and 2 microM, respectively. At saturating concentrations of AMP and fructose-2, 6-bisphosphate similar maximum activities were observed in the dependence of enzyme activity on the concentrations of fructose-6-phosphate. The fructose-6-phosphate affinity is more enhanced by fructose-2, 6-bisphosphate than by AMP.

Adenosine Monophosphate↗
PubMed1977

Binding of MgATP to yeast phosphofructokinase.

Binding of MgATP to yeast phosphofructokinase was investigated by the gel filtration equilibrium dialysis technique. Per subunit of yeast phosphofructokinase two molecules of MgATP are bound in the absence of fructose-6-phosphate, one to a high-affinity and one to a low-affinity site. The experimental data were compared with a kinetic model of yeast phosphofructokinase as described by Freyer et al. [3].

Adenosine Triphosphate↗
PubMed1976

The effect of temperature change on the kinetic behaviour of yeast phosphofructokinase.

Yeast phosphofructokinase does not exhibit any cold sensitivity. The kinetic properties of the enzyme have been investigated in the range between 10 degrees C and 30 degrees C in dependence on fructose 6-phosphate and ATP. Although a significant increase in the enzyme activity with rising temperature does not occur, the shape of the ATP velocity curves is not markedly altered. With increasing concentrations of fructose-6-phosphate the efficiency of temperature on the catalytic process increases, indicating a small temperature effect on the shape of the fructose-6-phosphate velocity curves. The results are interpreted in terms of an adequate kinetic model.

Adenosine Triphosphate↗
PubMed1975

[Effect of the replication of rubella virus on the protein biosynthesis of BHK 21 cell cultures].

The protein biosynthesis of BHK-21/C 13 cell cultures under the influence of multiplying rubella virus was studied by the uptake and incorporation of 14C leucine. The uptake of 14C leucine by the cells of virus-infected cultures was found to increase up to the third day after infection; no further increase was detectable on the fourth day. Control cultures maintained under the same conditions showed a similar behaviour up to the second and on the fourth day. On the third day, the virus-infected cultures exhibited significantly higher uptake than the controls. It may be that the virus infection causes damage to the cellular wall, the nature of which has yet to be elucidated. The protein incorporation of 14C leucine slightly increases in the virus-infected cultures 36 hrs after infection. This increase is not equally pronounced in the control cultures, but the differences were not significant.

Cell Line↗
PubMed1975

Reaction of yeast phosphofructokinase with succinic and maleic anhydride.

Modification of yeast phosphofructokinase by succinic and maleic anhydride influences the catalytic activity and the allosteric behaviour of the enzyme. Depending on the degree of succinylation and maleinylation a decrease of maximum activity, an increase of the apparent affinity for fructose-6-phosphate, a decrease of the Hill-coefficient and a diminution of ATP-inhibition are observed. Up to about 40% of the lysyl residues could be succinylated without dissociation of the hexameric protein, however with a decrease of the enzyme activity. More extensive succinylation or maleinylation causes a dissociation into subunits. The sedimentation coefficient is lowered from 20 S to about 3 S. The molecular weight of the smallest dissociation product was determined to 50 000 (+/- 10 000) by the sedimentation equilibrium method. The number of bound succinyl groups, as determined from radioactivity incorporation, exceeds the content of lysyl groups of the enzyme, indicating that the modifying reagent is also reacting with other amino acid residues.

Anhydrides↗