From Molecular Amphiphile to Tunable Esterase Mimics: Histidine‐Directed Cooperative Self‐Assembly Enables Efficient Ester Hydrolysis With Enantioselective Reactivity

ABSTRACT

Herein, we report a histidine‐functionalized pyrene amphiphile (PyHis) that self‐assembles in aqueous media to form catalytically active nanoarchitectures exhibiting pronounced esterase‐like activity. Spectroscopic and microscopic studies reveal cooperative π–π‐driven self‐assembly with an average hydrodynamic diameter of 685 ± 20 nm. The nanoassembled PyHis efficiently catalyzes the hydrolysis of p ‐nitrophenyl acetate under mild conditions (10 mM HEPES, pH 7.4, 35 °C), producing p ‐nitrophenolate with a clear time‐dependent absorbance increase at 405 nm. Kinetic analysis demonstrates Michaelis–Menten behavior with a low K _M of 5.75 µM and a catalytic efficiency ( k _cat / K _M ) of 65.21 M ^{− 1} s ^{− 1} , confirming enzyme‐like saturation kinetics. Control experiments with monomeric histidine derivatives and nonassembling analogues reveal up to a 6.3‐fold rate enhancement arising exclusively from supramolecular organization. The catalytic activity is strongly dependent on pH, temperature, and buffer composition, underscoring the role of microenvironment‐induced pK _a modulation of histidine residues. Notably, chiral Py‐L‐His assemblies exhibi measurable enantioselectivity ( k _L / k _D ∼ 1.5) toward phenylalanine‐derived esters. Thus, the current work establishes a clear structure–assembly–function relationship and introduces a minimalist supramolecular nanoenzyme platform for efficient ester hydrolysis under benign aqueous conditions.