Chemical arrows for enzymatic targets.
Reactive analogs of substrates or allosteric regulators can be designed to bind reversibly to particular ligand sites of enzymes. Subsequently, these compounds can react covalently with amino acids accessible from the ligand site, thereby functioning as chemical arrows aimed at specific enzymatic target sites. The approach of affinity labeling can be used to identify amino acid participants in active or regulatory sites, to provide a rational choice of targets for site-directed mutagenesis experiments, or to monitor conformational changes in the region of a particular enzyme site. Illustrations of these approaches include: 1) the use of reactive nucleotide analogs directed to substrate sites in adenylosuccinate synthetase and adenylosuccinate lyase and to regulatory sites of glutamate dehydrogenase, 2) the use of affinity cleavage by Fe2(+)-isocitrate to locate the metal-substrate site of isocitrate dehydrogenase, and 3) the use of reactive peptides and aromatic compounds to target the glutathione and xenobiotic sites of glutathione S-transferases.
Colman
R F
RF
Department of Chemistry and Biochemistry, University of Delaware, Newark 19716, USA.
D000241:Adenosine / Q000031:analogs & derivatives / Q000378:metabolism; D000265:Adenylosuccinate Synthase / Q000378:metabolism*; D000345:Affinity Labels; D000494:Allosteric Regulation; D001665:Binding Sites; D005969:Glutamate Dehydrogenase / Q000378:metabolism*; D005982:Glutathione Transferase / Q000378:metabolism*; D007521:Isocitrate Dehydrogenase / Q000378:metabolism*
D000345:Affinity Labels; C010959:5'-(4-fluorosulfonylbenzoyl)adenosine; D007521:Isocitrate Dehydrogenase; D005969:Glutamate Dehydrogenase; D005982:Glutathione Transferase; D000265:Adenylosuccinate Synthase; D000241:Adenosine