title: Product inhibition studies of yeast phosphoglycerate kinase evaluating properties of multiple substrate binding sites.
abstract: Product inhibition studies on yeast phosphoglycerate kinase (ATP:3-phospho-D-glycerate 1-phosphotransferase, EC 2.7.2.3) have been performed with 1,3-P2-glycerate. The results indicate that: 1. The catalytic reaction can be affected via four substrate binding sites, two for MgATP2- and two for 3-P-glycerate. 2. There is one catalytic centre per enzyme molecule. 3. The catalytic reaction primarily occurs at the 'first' or 'high affinity' MgATP2- and 3-P-glycerate binding sites. The 'second' set of sub-sites for these substrates are located in a region for regulation of the catalytic reaction. 4. The products of the reaction, 1,3-P2-glycerate and ADP, are preferentially bound to the regulatory region. 5. MgATP2- and 1,3-P2-glycerate are able to bind simultaneously to this region. When liganded with MgATP2- the apparent Ki value for 1,3-P2-glycerate increases from 3 microM to 20 microM.
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology; D001665:Binding Sites; D005994:Glycerophosphates / Q000494:pharmacology; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D008433:Mathematics; D010735:Phosphoglycerate Kinase / Q000037:antagonists & inhibitors*; D011485:Protein Binding; D012441:Saccharomyces cerevisiae / Q000201:enzymology*
chemical_list: D005994:Glycerophosphates; D000255:Adenosine Triphosphate; D010735:Phosphoglycerate Kinase; D008274:Magnesium