Biomaterial Database

Investigation of the quaternary structure of Neurospora pyruvate kinase by cross-linking with bifunctional reagents: the effect of substrates and allosteric ligands. 1977

M Kapoor, and M D O'Brien

Pyruvate kinase (EC 2.7.1.40) of Neurospora, a tetramer composed of apparently identical subunits, has been shown to be a dimer of dimers by interprotomeric cross-linking experiments in which bifunctional reagents were used. An analysis of the polyacrylamide gel profiles of the enzyme after cross-linking with glutaraldehyde, dimethyl suberimidate, and dimethyl adipimidate shows that the extent of intersubunit cross-linking is influenced markedly by the ligand bound to the enzyme. Bifunctional cross-linking reagents with a shorter distance between the two functional groups form cross-links effectively in the unliganded enzyme. In the FDP-pyruvate kinase complex, cross-linking was observed over longer distances compared with the unliganded enzyme. It is demonstrated that covalent cross-linkers cah be used as sensitive indicators of conformational changes induced in pyruvate kinase by substrates and allosteric ligands.

UI	MeSH Term	Description	Entries
D007094	Imides	Organic compounds containing two acyl groups bound to NITROGEN.	Imide
D008024	Ligands	A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)	Ligand
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D009491	Neurospora	A genus of ascomycetous fungi, family Sordariaceae, order SORDARIALES, comprising bread molds. They are capable of converting tryptophan to nicotinic acid and are used extensively in genetic and enzyme research. (Dorland, 27th ed)	Neurosporas
D009492	Neurospora crassa	A species of ascomycetous fungi of the family Sordariaceae, order SORDARIALES, much used in biochemical, genetic, and physiologic studies.	Chrysonilia crassa
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
D011487	Protein Conformation	The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).	Conformation, Protein,Conformations, Protein,Protein Conformations
D011770	Pyruvate Kinase	ATP:pyruvate 2-O-phosphotransferase. A phosphotransferase that catalyzes reversibly the phosphorylation of pyruvate to phosphoenolpyruvate in the presence of ATP. It has four isozymes (L, R, M1, and M2). Deficiency of the enzyme results in hemolytic anemia. EC 2.7.1.40.	L-Type Pyruvate Kinase,M-Type Pyruvate Kinase,M1-Type Pyruvate Kinase,M2-Type Pyruvate Kinase,Pyruvate Kinase L,R-Type Pyruvate Kinase,L Type Pyruvate Kinase,M Type Pyruvate Kinase,M1 Type Pyruvate Kinase,M2 Type Pyruvate Kinase,Pyruvate Kinase, L-Type,Pyruvate Kinase, M-Type,Pyruvate Kinase, M1-Type,Pyruvate Kinase, M2-Type,Pyruvate Kinase, R-Type,R Type Pyruvate Kinase
D004591	Electrophoresis, Polyacrylamide Gel	Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.	Polyacrylamide Gel Electrophoresis,SDS-PAGE,Sodium Dodecyl Sulfate-PAGE,Gel Electrophoresis, Polyacrylamide,SDS PAGE,Sodium Dodecyl Sulfate PAGE,Sodium Dodecyl Sulfate-PAGEs
D005976	Glutaral	One of the protein CROSS-LINKING REAGENTS that is used as a disinfectant for sterilization of heat-sensitive equipment and as a laboratory reagent, especially as a fixative.	Glutaraldehyde,Cidex,Diswart,Gludesin,Glutardialdehyde,Glutarol,Korsolex,Novaruca,Sekumatic,Sonacide,Sporicidin