Sterochemical probes of enzyme-catalyzed phosphotransfer reactions
Enzyme-catalyzed phospho group transfer reactions are of fundamental importance in biological systems. One of the primary goals of research on the reaction mechanisms of these enzymes is to distinguish between a double displacement pathway involving a phospho-enzyme intermediate and a single displacement pathway involving direct transfer of the phospho group with a ternary complex. The distinction between these two pathways has relied upon a number of experimental techniques, including the detection of a phospho-enzyme intermediate, the demonstration of partial exchange reactions, and the elucidation of the steady-state kinetic behavior. A more direct probe of the reaction mechanism, however, involves the determination of the stereochemical course of the reaction at phosphorus. The stereochemical approach has been used to determine the course of the several displacements at phosphorus catalyzed by the enzymes phosphoenolpyruvate synthetase and pyruvate, orthophosphate dikinase. First, 2-((R)-/sup 16/O, /sup 17/O, /sup 18/O)Phospho-d-glycerate has been synthesized and used to determine the stereochemical fate of the ..beta..-phospho group of ATP in these enzyme-catalyzed reactions. Secondly, adenosine 5'-O-(..gamma..S)-..beta gamma..-/sup 17/O,..gamma..-/sup 17/O, /sup 18/O)(3-thiotriphosphate) has been synthesized and used to determine the stereochemical fate of the ..gamma..-phospho group of ATP. A method for the analysis of the absolute configuration at phosphorus in D-fructose 2,6-(2-/sup 16/O,/sup 17/O,/sup 18/O)biphosphate has been developed.
- Research Organization:
- Harvard Univ., Boston, MA (USA)
- OSTI ID:
- 6898756
- Country of Publication:
- United States
- Language:
- English
Similar Records
Stereochemistry of phospho group transfer catalyzed by a mutant alkaline phosphatase
Stereochemical course of the reactions catalyzed by the bacterial phosphoenolpyruvate: Mannitol phosphotransferase system
Related Subjects
59 BASIC BIOLOGICAL SCIENCES
BIOLOGICAL PATHWAYS
CHEMICAL REACTIONS
ENZYME ACTIVITY
ENZYMES
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
NUCLEI
OXYGEN 16
OXYGEN 17
OXYGEN 18
OXYGEN ISOTOPES
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHORYLATION
PHOSPHOTRANSFERASES
STABLE ISOTOPES
STEREOCHEMISTRY
TRACER TECHNIQUES
TRANSFERASES