Self-Assembling Protein Nanostructures - Towards Active Functionality

摘要

This three year programme explored ways to engineer useful protein scaffolds that had functional components. The two objectives explored different approaches to this problem. Objective one successfully built high surface area nanoscaffolds from amyloid fibrils, and demonstrated that enzyme activity could be attached to this scaffold. These active nanoscaffolds were also embedded in permeable films and grown from surfaces. In the case of organophosphorous hydrolase, a significant increase in thermal stability was observed. Two papers were published in Biotechnology Progress and a new collaboration formed with Dr Charlene Mello (funded by ITC-PAC and SERDP). Objective two explored domain swapping to build higher order structures from model protein ribonuclease and the biophysical and biochemical properties of this thermally stable enzyme were retained, irrespective of the quaternary structure. This work was published in Biochemistry and Biophysics Research Communications. Attention then switched to a more versatile fold for catalysis, the (alpha-beta)8 barrel. A model thermophilic enzyme, natively a tetramer, was engineered as a monomer, a dimer (submitted to Biochimica et Biophysica Acta) and preliminary characterization of higher order structures was obtained. Quaternary structure altered activity a controlled way, opening up the potential of triggered assembly of protein structures.