Enhanced enzymatic activity and conformational stability of catalase in presence of tetrahedral DNA nanostructures: A biophysical and kinetic study

Abstract

The emergence of DNA nanotechnology has shown enormous potential in a vast array of applications, particularly in the medicinal and theranostics fields. Nevertheless, the knowledge on the biocompatibility between DNA nanostructures and cellular proteins is largely unknown. Herein, we report the biophysical interaction between proteins (circulatory protein bovine serum albumin, BSA, and the cellular enzyme bovine liver catalase, BLC) and tetrahedral DNA (tDNA), which are well-known nanocarriers for therapeutics. Interestingly, the secondary conformation of BSA or BLC was unaltered in the presence of tDNAs which supports the biocompatible property of tDNA. In addition, thermodynamic studies showed that the binding of tDNAs with BLC has a stable non-covalent interaction via hydrogen bond and van der Waals contact, which is indicative of a spontaneous reaction. Furthermore, the catalytic activity of BLC was increased in the presence of tDNAs after 24 h of incubation. These findings indicate that the presence of tDNA nanostructures not only ensures a steady secondary conformation of proteins, but also stabilize the intracellular proteins like BLC. Surprisingly, our investigation discovered that tDNAs have no effect on albumin proteins, either by interfering or by adhering to the extracellular proteins. These findings will aid in the design of future DNA nanostructures for biomedical applications by increasing the knowledge on the biocompatible interaction of tDNAs with biomacromolecules.