title: The allosteric effect of fructose bisphosphate on muscle pyruvate kinase studied by infrared spectroscopy.
abstract: 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+), K(+), 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 of 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.
authors.affiliation: Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden. saroj@dbb.su.se
authors.forename: Saroj
authors.initials: S
authors.lastname: Kumar
authors.forename: Andreas
authors.initials: A
authors.lastname: Barth
mesh_terms: D000494:Allosteric Regulation; D017666:Deuterium Oxide / Q000737:chemistry; D005635:Fructosediphosphates / Q000737:chemistry* / Q000378:metabolism; D007477:Ions / Q000737:chemistry; D008670:Metals / Q000737:chemistry; D011485:Protein Binding; D011770:Pyruvate Kinase / Q000737:chemistry* / Q000378:metabolism; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D005635:Fructosediphosphates; D007477:Ions; D008670:Metals; D011770:Pyruvate Kinase; D017666:Deuterium Oxide; C029063:fructose-1,6-diphosphate