Article Figures & Data
Figures
- FIG. 1.
SDS-PAGE of the native PFK1 enzyme purified to near homogeneity. In the left lane of the gel, the following standards are shown: phosphorylase (molecular weight, 97,000), bovine serum albumin (66,200), ovalbumin (45,000), carbonic anhydrase (31,000), trypsin inhibitor (21,500), and lysozyme (14,400).
- FIG. 2.
Citrate inhibition of the native PFK1 enzyme as measured in the presence of 5 mM Mg2+ ions and 1 mM ATP in the system and different concentrations of fructose-6-phosphate (F6P) as indicated on the figure.
- FIG. 3.
Inhibition coefficient (Ki) for citrate as determined at different concentrations of magnesium ions in the systems and under the conditions described in the legend of Fig. 2.
- FIG. 4.
Activities of the native PFK1 enzyme measured with and without various concentrations of ammonium ions as recorded in the system with 1 mM ATP and 5 mM Mg2+ ions.
- FIG. 5.
Hill plot of PFK1 activities of the native PFK1 protein as determined at different ammonium ion concentrations.
- FIG. 6.
Citrate inhibition of the native PFK1 enzyme measured in the presence of ammonium ions (1 mM), 1 mM ATP, 5 mM Mg2+, and different concentrations of fructose-6-phosphate (F6P) as indicated on the figure.
- FIG. 7.
Activities of the shorter 49-kDa PFK1 fragment measured at increasing concentrations of citrate and various activators. The measuring system contained 0.5 mM ATP, 6 mM fructose-6-phosphate, and 5 mM Mg2+ ions.
- FIG. 8.
Activities of the native PFK1 (A) and a shorter 49-kDa fragment (B) measured without and in the presence of various concentrations of AMP as indicated on the figure.
- FIG. 9.
Multiple sequence alignment of deduced amino acid residues of N-terminal and C-terminal parts of PFK1 proteins, where binding sites for citrate (gray) are located. ECOLI, E. coli (P0A796); ASPNG, A. niger (P78985), YEAST1, S. cerevisiae (P16861); YEAST2, S. cerevisiae (P16862); RABBIT, Oryctolagus cuniculus (P00511). Dashes represent gaps introduced into a sequence for alignment.
