ADPbound
ADPbound is a descriptive term used in biochemistry and structural biology to denote a protein or enzyme in which an adenosine diphosphate molecule is bound at a nucleotide-binding site, typically after hydrolysis of ATP. Across many families of nucleotide-binding proteins, function cycles through ATP-bound, ADP-bound, and nucleotide-free states, with the ADP-bound state often corresponding to a post-hydrolysis conformation that influences activity and interactions. The ADP-bound conformation can alter the geometry of the catalytic pocket, modulate affinity for substrates or regulatory partners, and bias the protein toward specific structural states.
In structural studies, ADP-bound forms are commonly observed in X-ray crystallography, cryo-electron microscopy, and NMR analyses
Applications include understanding mechanism, informing drug design that stabilizes the ADP-bound state, and interpreting disease-related mutations