Biological Activity
Necrostatin-5 is an inhibitor of necroptosis (non-apoptotic cell death pathway) by indirect inhibition of RIP1 kinase. Necroptosis is defined as alternative active cell death pathway: Death-Domain Receptor (DRs, e.g. Fas/TNFR) mediated and caspase-inhibitor insensitive with specific morphology (nuclear condensation, organelle swelling, loss of plasma membrane integrity). The necrostatins have been discovered to inhibit this pathway by inhibition of the death domain receptor-associated adaptor kinase RIP1. Three distinct mechanisms appear to be involved: T-loop dependent inhibition by necrostatin-1; partially T-loop independent inhibition by necrostatin-3 and indirect inhibition of RIP1 by necrostatin-5, since necrostatin-5 is a potent inhibitor of immunnoprecipitated RIP1, but does not inhibit recombinant RIP1.