Solution X-ray scattering studies of the yeast phosphofructokinase allosteric transition. Characterization of an ATP-induced conformation distinct in quaternary structure from the R and T states of the enzyme.

The allosteric transition of yeast phosphofructokinase has been studied by solution x-ray scattering. The scattering curves corresponding to the native enzyme (T conformation) were found to be similar to the curves recorded in the presence of saturating concentrations of fructose 6-phosphate (R conformation) or AMP (R or R' conformation). However, the curves obtained in the presence of ATP are clearly different: the radius of gyration increases and the secondary minima and maxima are systematically shifted to lower angles, suggesting a swelling of the enzyme in the presence of ATP.

Studies on the structure of yeast phosphofructokinase.

In this paper, we describe an efficient procedure for the purification of yeast phosphofructokinase. This procedure eliminates any time delay and enables to obtain an enzyme with minimum proteolytic alterations. The molecular weights of the oligomeric enzyme and of its constitutive subunits were both evaluated by means of several independent methods.

Structural and functional consequences of subunit interactions in glyceraldehyde 3-phosphate dehydrogenase.

A variety of species of GPDH undergo acylation at two of the four active cystein sites per mole of tetrameric enzyme. This reaction requires tightly bound NAD+, a situation restricted to two of the four NAD sites per tetramer. S leads to N acyl transfer from cysteins to lysine in the diacyl enzyme yields an inactive enzyme.

Sulfhydryl groups of yeast phosphofructokinase-specific localization on beta subunits of fructose 6-phosphate binding sites as demonstrated by a differential chemical labeling study.

Yeast phosphofructokinase contains 83 +/- 2 cysteinyl residues/enzyme oligomer. On the basis of their reactivity toward 5,5-dithiobis(2-nitrobenzoic acid), the accessible cysteinyl residues of the native enzyme may be classified into three groups. For titrations performed with N-ethylmaleimide, subdivisional classes of reactivity are evidenced.