Insights from affinity labeling into nucleotide- and coenzyme-dependent enzyme catalysis and regulation

Affinity labeling using reactive nucleotide analogues can locate an enzyme's catalytic and/or regulatory nucleotide site and map the amino acid residues accessible from that binding site. This article first summarizes the classes of nucleotide affinity labels available. It then illustrates how such compounds have been used to provide insights into the function and structure of nucleotide-binding enzymes, as exemplified by adenylosuccinate lyase, adenylosuccinate synthetase, glutamate dehydrogenase and cAMP phosphodiesterase.