The concept of substrate inhibition to prevent its phosphorylation has potential in drug discovery and is envisioned to treat the autoimmune disorder multiple sclerosis (MS). Glia maturation factor-β (GMF-β) Ser83 phosphorylation by protein kinase A (PKA) is pivotal in the activation of GMF-β-p38MAPK-NFκB biochemical pathway towards proinflammatory response induction in experimental autoimmune encephalomyelitis (EAE). Using structure-based drug design, we identified the small molecule inhibitor 1-H-indazole-4yl methanol (GMFBI.1) that specifically blocked Ser83 phosphorylation site on GMF-β substrate. Using in vitro and in vivo techniques, molecular mechanism of action of GMFBI.1's direct interaction with GMF-β substrate and prevention of its Ser83 phosphorylation was established. GMFBI.1 down regulated p38MAPK phosphorylation and NFκB expression essential for proinflammatory response. Further, GMFBI.1 administration at peak of EAE reversed clinical symptoms, immunopathology, proinflammatory cytokine response and up regulated the anti-inflammatory cytokines. Present strategy of substrate inhibition against the key immunomodulatory target has immense therapeutic potential in MS. Multiple sclerosis is a chronic autoimmune, demyelinating, neurodegenerative disorder of the central nervous system (CNS) affecting 2.5 million people globally 1,2. Despite different disease-modifying therapies adopted to mitigate the inflammatory milieu of MS using different drugs 3-5 , patient's progress from an acute phase to a stage with considerable neurological disabilities. Current therapies modulate disease differently as they target activated T cells, antigen presenting cells or prevent the egress of T cells into brain. Importantly, none of these drugs control molecules that modulate the proinflammatory response at a fundamental level following infiltration of activated T and B lymphocytes 6,7. Activated lymphocytes undergo clonal expansion assisted by the cytokines produced mainly by astrocytes and microglia and glia maturation factor-β (GMF-β) plays an instrumental role in cytokine induction 8,9. Thus, targeting GMF-β could signify a novel approach in controlling the immune response in the brain. Over expression of GMF-β in response to immune challenge up regulates p38MAPK and NFκB expression in astrocytes leading to increased GM-CSF production by astrocytes and microglial generation of TNF-α, IL1-β, IL-6 and IFN-γ, augmenting proinflammatory response 10-12. In the well-established EAE animal model of MS,

No abstract