A di-Copper Peptidyl Complex Mimics the Activity of Catalase, a Key Antioxidant Metalloenzyme

International audienceCatalases (CAT) are antioxidant metalloenzymes necessary for life in oxygen-metabolizing cells to regulate H 2 O 2 concentration by accelerating its dismutation. Many physio-pathological situations are associated with oxidative stress resulting from H 2 O 2 overproduction during which antioxidant defenses are overwhelmed. We have used a combinatorial approach associated with an activity-based screening to discover a first peptidyl di copper complex mimicking CAT. The complex was studied in detail and characterized for its CAT activity both in solution and in cells using different analytical methods. The complex exhibited CAT activity in solution and, more interestingly, on HyPer HeLa cells which possess a genetically encoded ratiometric fluorescent sensors of H 2 O 2. These results highlight the efficiency of a combinatorial approach for the discovery of peptidyl complexes that exhibit catalytic activity