Brown C E, Taylor J M, Chan L M
Biochim Biophys Acta. 1985 Jul 1;829(3):342-7. doi: 10.1016/0167-4838(85)90242-0.
The interaction of fructose 1,6-bisphosphate, phosphoenolpyruvate and ADP with pyruvate kinase (ATP: pyruvate 2-O-phosphotransferase, EC 2.7.1.40) from yeast and rabbit muscle has been studied as a function of pH utilizing the quenching of protein fluorescence at 330 nm by these ligands. Both the muscle and the yeast pyruvate kinase interact with either ADP or phosphoenolpyruvate with similar affinity, indicating that the substrate-binding sites for these two isozymes are similar. The major difference between the yeast and muscle isozymes is their affinity with fructose 1,6-bisphosphate. Fructose 1,6-bisphosphate interacts with the yeast isozyme in orders of magnitude more strongly than with the muscle isozyme. Moreover, the affinity of fructose 1,6-bisphosphate to the yeast isozyme is strongly pH-dependent, while the interaction of fructose 1,6-bisphosphate with the muscle isozyme is independent of pH. The data indicate that yeast pyruvate kinase undergoes a conformational change as the pH is increased from 6.0 to 8.5.
利用这些配体对330nm处蛋白质荧光的淬灭作用，研究了来自酵母和兔肌肉的果糖1,6 - 二磷酸、磷酸烯醇丙酮酸和ADP与丙酮酸激酶（ATP：丙酮酸2 - O - 磷酸转移酶，EC 2.7.1.40）的相互作用与pH的关系。肌肉和酵母的丙酮酸激酶与ADP或磷酸烯醇丙酮酸相互作用的亲和力相似，表明这两种同工酶的底物结合位点相似。酵母和肌肉同工酶之间的主要差异在于它们与果糖1,6 - 二磷酸的亲和力。果糖1,6 - 二磷酸与酵母同工酶的相互作用比与肌肉同工酶的相互作用强几个数量级。此外，果糖1,6 - 二磷酸对酵母同工酶的亲和力强烈依赖于pH，而果糖1,6 - 二磷酸与肌肉同工酶的相互作用则与pH无关。数据表明，随着pH从6.0增加到8.5，酵母丙酮酸激酶会发生构象变化。
