Coordination of manganous ion at the active site of pyruvate, phosphate dikinase: the complex of oxalate with the phosphorylated enzyme

Journal Article · Tue Jun 28 04:00:00 EDT 1988 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00413a030· OSTI ID:7039547

Kofron, J L; Ash, D E; Reed, G H

Electron paramagnetic resonance spectroscopy has been used to investigate the structure of the complex of manganous ion with the phosphorylated form of pyruvate, phosphate dikinase (E/sub p/) and the inhibitor oxalate. Oxalate, an analogue of the enolate of pyruvate, is competitive with respect to pyruvate in binding to the phosphorylated form of the enzyme. Superhyperfine coupling between the unpaired electrons of Mn(I) and ligands specifically labeled with /sup 17/O has been used to identify oxygen ligands to Mn(II) in the complex with oxalate and the phosphorylated form of the enzyme. Oxalate binds at the active site as a bidentate chelate with Mn(II). An oxygen from the 3'-N-phosphohistidyl residue of the protein is in the coordination sphere of Mn(II), and at least two water molecules are also bound to Mn(II) in the complex. Oxalate also binds directly to Mn(II) in a complex with nonphosphorylated enzyme. The structure for the E/sub p/-Mn(II)-oxalate complex implies that simultaneous coordination of a phospho group and of the attacking nucleophile to the divalent cation is likely an important factor in catalysis of this phospho-transfer reaction.

• Research Organization: Univ. of Wisconsin, Madison (USA)
• OSTI ID: 7039547
• Journal Information: Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 27:13; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
CARBOXYLIC ACID SALTS
CATIONS
CHARGED PARTICLES
COMPLEXES
DEUTERIUM COMPOUNDS
ELECTRON SPIN RESONANCE
ENZYMES
EVEN-ODD NUCLEI
HYDROGEN COMPOUNDS
HYPERFINE STRUCTURE
IONS
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MANGANESE COMPOUNDS
MOLECULAR STRUCTURE
NUCLEI
OXALATES
OXYGEN 17
OXYGEN ISOTOPES
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHOTRANSFERASES
RESONANCE
STABLE ISOTOPES
TRANSFERASES
TRANSITION ELEMENT COMPOUNDS