Probing into the binding mechanism of phosphorus(V)-corrole with hemoglobin using photophysical and computational approach.

Phosphorus containing corroles are a promising category of functional macrocyclic compounds with significant biomedical applications, especially in photodynamic treatment (PDT). Despite their increasing significance, mechanistic understanding of their interactions with biological macromolecules particularly transport proteins, is remains predominantly unexplored. In this study, we report for the first time the binding interaction of a novel phosphorus-substituted corrole (1P) with human haemoglobin (Hb), a heme-containing tetrameric protein essential for systemic transport and therapeutic efficacy. This study uses an integrated spectroscopic and computational approach. Our spectroscopic findings suggested the formation of a stable ground-state complex between corrole and Hb. At 303 K, the binding constant (Kb = 3.72 × 105) and change in Gibbs free energy (∆G = -32.3 kJmol− 1) suggested a spontaneous and favorable Hb-corrole interaction. Molecular docking results further support these findings, with a docking score of -3.92 kcal/mol. The MMGBSA study revealed binding free energies of -35.01 kcal/mol suggesting a strong and energetically favourable interaction. Moreover, hydrogen bonding and RMSD/Rg analysis further validated complex stability. Overall, these findings highlight a strong affinity between corrole and Hb, suggesting that hemoglobin could serve as a potential transport carrier, providing novel insights into hemoprotein-mediated drug delivery and therapeutic uses.