Direct observation of assembly and function of trigger responsive lipase biohybrids

Protein-polymer biohybrids mark a cutting edge in the creation of advanced materials designed for high performance under diverse conditions by combining the intrinsic stability and adaptability of synthetic polymers with the remarkable functionality and specificity of proteins. Despite the existence of stimuli responsive polymers, their potential for achieving precise, trigger responsive control over both the function and the assembly of protein-polymer biohybrids has yet to be fully attained. Here, we report the synthesis and thorough characterization of pH and temperature responsive lipase-polymer conjugates at both the supramolecular and the single molecule level. In contrast to conventional ensemble measurements performed in solution, we extensively characterized the stimuli triggered reversibility of the self-assembly of these lipase-based biohybrids and recorded the enzymatic activity at the fundamental level of individual nanoparticles. Our findings unexpectedly demonstrated that the stimuli responsive biohybrids exhibited not only a twofold increased enzymatic activity as compared to native lipases in certain cases but also maintained the trigger responsive control over enzymatic activity by temperature. Direct single particle recordings of biohybrid activity showed a correlation of the biohybrid size to catalytic activity, revealing individual enzymes to display higher activity in smaller nanoparticles. The biohybrids exhibit impressive long-term stability, in some cases almost 95% of the enzymatic activity as compared to ∼40-60% for native lipases after 1 year of storage. The improved stability and activity as compared to native enzymes accompanied with their triggered responsiveness highlight their significant potential for tightly controlled biocatalysis and sustainable industrial applications.