Spatiotemporal Control Over Biosupramolecular Assembly and Catalysis

Abstract

Supramolecular self-assembly is a critical process in living organisms, precisely regulated to occur at specific times and locations through complex reaction-diffusion mechanisms.1 This regulation is essential for various cellular functions, relying on the spatiotemporal control of directed self-assembly mediated by enzymatic activity, independent of external stimuli. Despite its importance in bridging supramolecular chemistry to biomedicine, the potential of complex biosupramolecular assembly to influence spatiotemporally tunable assembly formation, colloidal transport, catalysis, or phoresis has yet to be fully explored. To achieve this, first, we investigated the spatiotemporal dynamics of surfactant self-assembly driven by adenosine triphosphate (ATP) and its degrading enzymes. Alkaline phosphatase (ALP) produces transient assemblies, while hexokinase (HK) promotes sustained assemblies. We established concentration gradients of enzymes and surfactants to program self-assembly in two-dimensional space, demonstrating a novel method for achieving spatial adaptability in self-organized systems.2 We also explored the assembly of three enzymes involved in cascade reactions at the oil-water interface stabilized by a Zn(II)-metallosurfactant. Catalytically active clusters were formed in a binary mixture with a non-catalytic surfactant, with catalytic activity modulated by phosphate ions. This work underscores the functional diversity of supramolecular nanoarchitectonics at interfaces.3 Next, we investigated the phoretic behavior of a biocolloid composed of a Zn(II)-coordinated metallomicelle and the enzymes horseradish peroxidase (HRP) and glucose oxidase (GOx) under microfluidic conditions. We demonstrated that an ATP-independent oxidative biocatalytic product formation zone can be modulated by glucose and ATP gradients, revealing that transport direction and extent can be adjusted without ATPase involvement.4 Additionally, we developed an effective method for unactivated phosphoester hydrolysis, converting stable nucleotides to nucleosides using a biosupramolecular system formed by ALP and a Zn(II)-metallosurfactant. This system selectively activates or inhibits ALP-mediated oligonucleotide digestion. The enhanced binding affinity of the Zn(II)-containing headgroup for phosphate substrates significantly reduces the Michaelis constant (KM) and increases the turnover rate (kcat). Isothermal titration calorimetry revealed thermodynamic changes during binding and catalytic cleavage, highlighting the potential of Zn(II)-mediated interactions for advancing biocatalytic circuits in nucleic acid-based drug delivery and bioimaging.5 Overall, our research highlights the potential of complex biosupramolecular assemblies to enhance both transport phenomena and catalytic efficiency, paving the way for advancements in biomedicine and targeted delivery systems. The ability to modulate assembly behavior through concentration gradients and enzyme interactions opens new possibilities for designing sophisticated biocatalytic circuits.