Fructose-1,6-diphosphate, binding sites

From a study of the P n.m.r. spectra of phosphoribosyl diphosphate in the presence of magnesium ions, it has been deduced that the mono- and pyrophosphate residues act as independent binding sites for these ions. The anomeric composition and mutarotation rate of fructose 1,6-bisphosphate has been determined by P n.m.r., and it has also been observed that magnesium and zinc ions bind preferentially to the 1-phosphoryl group when it is in the a-ano-meric position. ... 

On the basis of preferential affinities for three different peptide binding sites of the pigeon liver fatty acid synthetase, Ghesterton et al. (1968b) have suggested a regulator role for the ratio of concentrations of acetyl-GoA malonyl-GoA. The competitive effects of acetyl-GoA malonyl-GoA, NADHiNAD", phosphorylated compounds (e.g., fructose 1,6-diphosphate), palmityl-GoA, and free coenzyme A (Brady et al., 1956 Robinson et al., 1963) at concentrations which are... 

In order to give useful information about an enzyme, a conformationally restricted active-site-directed analog inhibitor need not bind to the enzyme irreversibly. In a study of the enzyme fructose 1,6-diphosphatase from rabbit liver, Benkovic et al, have investigated the question of the reactive form of the fructose 1,6-diphosphate in the enzymatic process (104,105). Three likely forms are shown in structures 50, 51 and 52. 

Steady-state kinetics studies of the inhibition of the enzyme by oxR-mate and oxalate 203) hinted at the existence of enzyme-oxamate complexes. No binding of 0.15 milf oxamate was detected in the ultracentrifuge. However, Siidi 283) reported that oxalate (15 mM) and oxamate (60 mM) protect M4 enzyme from heat denaturation. Oxaloacetate and fructose 1,6-diphosphate are effective at protecting against thermal denaturation at 1 mM concentration 286). It is possible that these anions bind at sites similar to those detected in the dogfish M4 LDH molecule 139). 

Cl relaxation of the perchlorate ion in the presence of various proteins is presently being studied in our laboratory. Of the results obtained so far may be mentioned the demonstration of an effect of CIO on the molecular mobility at the active site anion binding region of fructose-1,6-diphosphate aldolase [1Z6]. Thus addition of fructose-1,6-diphosphate is accompanied by a decreased Cl relaxation rate -6f both Cl and CIO and comparisons of T and... 

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