Self-Activated Nucleases Formulation Based on Metal–Organic Frameworks with Enhanced Activity and Stability

Nucleases are widely used tools for cleaving phosphodiester bonds in DNA in molecular biology research, medical diagnosis, and disease treatment. However, their inherently fragile nature limits their practical applications. Metal–organic frameworks (MOFs) have emerged as solid supports for enzyme immobilization. But, the immobilized enzymes usually exhibit low catalytic activity and low enzyme availability. In this study, for the first time in the literature, we developed a self-activated nuclease formulation based on squaric acid-based MOFs for efficient enzyme activation and protection from harsh environments. Deoxyribonuclease I (DNase I) and its cofactors (Ca2+ and Mg2+, Mn2+, or Co2+) were encapsulated in a suitable MOF via a water-based de novo approach. These MOF carriers improved the stability of DNase I against perturbation environments (heating, treatment with an organic solvent, vortexing, and freeze–thawing) and released the enzymes and their cofactors during catalysis, enabling the conversion of the enzyme from its inactive to active form. Moreover, the squarate ligands disintegrated from the MOFs can serve as metal chelators, protecting DNase I from the inhibitory effects of Na+ and K+. This multifunctional nuclease formulation combines enzyme protection, self-activation, and customized catalysis. This formulation was also applied to other nucleases, alkaline phosphatase (ALP) and deoxyribonuclease II (DNase II), which exhibited enhanced activity and stabilities. This study opens a new avenue for the facile preparation, storage, and transportation of nucleases, thus promoting their practical applications.