The Allosteric Effect of Fructose Bisphosphate on Muscle Pyruvate Kinase Studied by Infrared Spectroscopy

作者：Kumar Saroj^*; Barth Andreas

来源：Journal of Physical Chemistry B, 2011, 115(39): 11501-11505.

DOI：10.1021/jp206272x

Pyruvate kinase exhibits allosteric properties. The allosteric effect of fructose 1,6-bisphosphate (FBP) on phosphoenolpyruvate (PEP) binding to rabbit muscle pyruvate kinase (PK) in the presence of various ions (mg(2+), mn(2+), Na(+)) was studied by attenuated total reflection infrared spectroscopy in combination with a dialysis accessory. The experiments indicated that FBP binding causes conformational changes of PK that are of the same order of magnitude as those of PEP binding. The conformational change of PEP binding to PK/Mg(2+)/K(+) in the presence of FBP was about twice as large as in its absence, which is tentatively ascribed to a higher occupancy the closed state. The affinity for PEP increased in the presence of Mg(2+) and K(+). No such effects were observed with the other ion combinations Mn(2+)/K(+) and Mg(2+)/Na(+) or in D(2)O (with Mg(2+)/K(+)), and therefore we did not detect an allosteric effect on PEP binding under these conditions.

• 出版日期2011-10-6