Understanding the Role of Surfactants in the Interaction and Hydrolysis of Myoglobin by Zr‐MOF‐808

Controlled protein hydrolysis is an important procedure in proteomics applications and is used to aid the understanding of protein structure and function. The hydrolysis of hydrophobic proteins is particularly challenging, as due to their poor solubility the use of surfactants, which typically inactivate natural enzymes, is often required. Such limitations of natural enzymes prompted the development of chemical catalysts for the selective hydrolysis of proteins. In this study, the nanozymatic potential of MOF-808, a Zr6O8 based metal organic framework, has been investigated towards protein hydrolysis in the presence of several surfactants which differ in structure and polarity. The influence of ionic SDS (sodium dodecyl sulfate), neutral TX-100 (Triton X-100) and zwitterionic Zw3-12 (n-dodecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate) and CHAPS (3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate) surfactants on the hydrolysis of horse heart myoglobin in the presence of MOF-808 has been examined. The hydrolysis of horse heart myoglobin by MOF-808 was followed using sodium dodecyl sulfate poly(acrylamide) gel electrophoresis (SDS-PAGE), which showed that nanozymatic activity of MOF-808 can be tuned by using appropriate surfactants. To understand the observed reactivity patterns, the interactions between surfactant, MOF and protein were further investigated using a range of spectroscopic methods, which included Dynamic Light Scattering (DLS), H-1 NMR, UV-Vis, Circular Dichroism and UV-Vis Spectroscopy. While the presence of SDS increased the number of observed peptide fragments due to protein unfolding and increased protein-MOF interaction, the use of zwitterionic and neutral surfactant reduced the hydrolytic efficiency, most likely by hindering the efficient protein-MOF interaction.