Characterisation of utrophin modulator SMT C1100 as a non-competitive inhibitor of firefly luciferase.

Firefly luciferase (FLuc) is a powerful tool for molecular and cellular biology, and popular in high-throughput screening and drug discovery. However, FLuc assays have been plagued with positive and negative artefacts due to stabilisation and inhibition by small molecules from a range of chemical classes. Here we disclose Phase II clinical compound SMT C1100 for the treatment of Duchenne muscular dystrophy as an FLuc inhibitor (KD of 0.40 ±â€¯0.15 µM). Enzyme kinetic studies using SMT C1100 and other non-competitive inhibitors including resveratrol and NFκBAI4 identified previously undescribed modes of inhibition with respect to FLuc's luciferyl adenylate intermediate. Employing a photoaffinity strategy to identify SMT C1100's binding site, a photolabelled SMT C1100 probe instead underwent FLuc-dependent photooxidation. Our findings support novel binding sites on FLuc for non-competitive inhibitors.

Electrocatalytic Volleyball: Rapid Nanoconfined Nicotinamide Cycling for Organic Synthesis in Electrode Pores.

In living cells, redox chains rely on nanoconfinement using tiny enclosures, such as the mitochondrial matrix or chloroplast stroma, to concentrate enzymes and limit distances that nicotinamide cofactors and other metabolites must diffuse. In a chemical analogue exploiting this principle, nicotinamide adenine dinucleotide phosphate (NADPH) and NADP+ are cycled rapidly between ferredoxin-NADP+ reductase and a second enzyme-the pairs being juxtaposed within the 5-100 nm scale pores of an indium tin oxide electrode. The resulting electrode material, denoted (FNR+E2)@ITO/support, can drive and exploit a potentially large number of enzyme-catalysed reactions.