Discrete-time quantum walks reveal critical residues involved in long-range interactions in proteins

Discrete-time quantum walks on protein contact networks identify residues with delocalized, long-range interaction behavior, and experimental tests in AsLOV2 (PDB: 2V0U) support their role in photosensing.

• Why it matters: Long-range residue communication underlies signal transmission, conformational regulation, and catalysis, but pinpointing the mediating residues remains difficult.
• What they did: The framework uses discrete-time quantum walk dynamics on protein structures, using normalized time-averaged transition probabilities for interaction strength and Shannon entropy to flag delocalized residues. It is experimentally validated in AsLOV2 (PDB: 2V0U) via site-directed mutagenesis, protein purification, and dark-recovery kinetics.
• The result: The predicted residues are reported as structurally and functionally important in literature and are shown to be important for understanding photosensing mechanisms in AsLOV2, enabling a scalable, interpretable prediction method without molecular dynamics or prior functional annotation.