Abstract
Integrin-linked kinase (ILK), a β1-integrin cytoplasmic domain interacting protein, supports multi-protein complex formation. ILK-1 is involved in neurodegenerative diseases by promoting neuro-inflammation. On the other hand, its overexpression induces epithelial-mesenchymal transition (EMT), which is a major hallmark of cancer and activates various factors associated with a tumorigenic phenotype. Thus, ILK-1 is considered as an attractive therapeutic target. We investigated the binding affinity and ILK-1 inhibitory potential of noscapine (NP) using spectroscopic and docking approaches followed by enzyme inhibition activity. A strong binding affinity of NP was measured for the ILK-1 with estimated Ksv (M-1) values of 1.9 × 105, 3.6 × 105, and 4.0 × 105 and ∆G0 values (kcal/mol) -6.19554, -7.8557 and -8.51976 at 298 K, 303 K, and 305 K, respectively. NP binds to ILK-1 with a docking score of -6.6 kcal/mol and forms strong interactions with active-site pocket residues (Lys220, Arg323, and Asp339). The binding constant for the interaction of NP to ILK-1 was 1.04 × 105 M-1, suggesting strong affinity and excellent ILK-1 inhibitory potential (IC50 of ∼5.23μM). Conformational dynamics of ILK-1 were also studied in the presence of NP. We propose that NP presumably inhibits ILK-1-mediated phosphorylation of various downstream signalling pathways that are involved in cancer cell survival and neuroinflammation.