title: Distinguishing the chemical moiety of phosphoenolpyruvate that contributes to allostery in muscle pyruvate kinase.
abstract: A series of substrate analogues has been used to determine which chemical moieties of the substrate phosphoenolpyruvate (PEP) contribute to the allosteric inhibition of rabbit muscle pyruvate kinase by phenylalanine. Replacing the carboxyl group of the substrate with a methyl alcohol or removing the phosphate altogether greatly reduces substrate affinity. However, removal of the carboxyl group is the only modification tested that removes the ability to allosterically reduce the level of Phe binding. From this, it can be concluded that the carboxyl group of PEP is responsible for energetic coupling with Phe binding in the allosteric sites.
authors.affiliation: Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, Kansas City, KS 66160, USA.
authors.forename: James M
authors.initials: JM
authors.lastname: Urness
authors.forename: Kelly M
authors.initials: KM
authors.lastname: Clapp
authors.forename: J Cody
authors.initials: JC
authors.lastname: Timmons
authors.forename: Xinyan
authors.initials: X
authors.lastname: Bai
authors.forename: Nalin
authors.initials: N
authors.lastname: Chandrasoma
authors.forename: Keith R
authors.initials: KR
authors.lastname: Buszek
authors.forename: Aron W
authors.initials: AW
authors.lastname: Fenton
mesh_terms: D000494:Allosteric Regulation; D000495:Allosteric Site; D000818:Animals; D009132:Muscles / Q000737:chemistry / Q000201:enzymology*; D010649:Phenylalanine / Q000378:metabolism*; D010728:Phosphoenolpyruvate / Q000031:analogs & derivatives / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D011770:Pyruvate Kinase / Q000737:chemistry / Q000378:metabolism*; D011817:Rabbits; D013379:Substrate Specificity
chemical_list: D010649:Phenylalanine; D010728:Phosphoenolpyruvate; D011770:Pyruvate Kinase