Lactoferrin amyloid-templated gold nanozymes combat pathogenic Bacteria via a synergistic assault of oxidative stress and metabolic collapse.

The escalating crisis of antibacterial resistance necessitates the development of novel therapeutic agents that operate via unconventional mechanisms. Herein, we report the design of a potent antibacterial nanozyme by engineering a food-grade protein, lactoferrin (LF), into a dual-function biological macromolecule template. Lactoferrin was first transformed into robust amyloid fibrils (LFF), which then served as an active scaffold for the in situ synthesis of gold nanoclusters (AuNCs@LFF). The resulting hybrid material exhibited robust peroxidase-like (POD-like) activity, efficiently catalyzing the conversion of H₂O₂ into cytotoxic hydroxyl radicals (·OH). Mechanistic investigations revealed a multi-pronged antibacterial strategy against both Staphylococcus aureus and Salmonella paratyphi B. The LFF scaffold promoted strong adhesion to the bacterial surface, facilitating membrane disruption and the targeted delivery of ROS. Beyond this direct oxidative damage, untargeted metabolomics unveiled an intracellular catastrophic collapse of central metabolism. This collapse was initiated by a profound depletion of essential cofactors (NAD+, CoA, TPP), which triggered the paralysis of the TCA cycle and a subsequent failure in the synthesis of amino acids, nucleotides, and cell wall precursors. This study demonstrates that the potent bactericidal effect arises from a synergistic assault, combining membrane oxidative damage with an internal cofactor collapse that leads to metabolic death. This work elucidated the novel mechanism for designing intelligent, macromolecule-based nanozymes that target the vulnerable hub of cofactor metabolism in pathogenic bacteria.