(743e) Protein Confinement in Mesoporous Silica – Effects of Surface Curvature Investigated By Neutron Scattering and Catalysis

Confinement of biomolecules in structured mesoporous materials offers advantages in both biological and synthetic systems¹. The application of these systems spans a diverse range of purposes, from industrial production of biofuels to laboratory-on-a-chip diagnosis and controlled drug delivery. Therefore, it is necessary to develop a fundamental understanding of biomolecular confinement. Our previous studies on confinement effects in the ordered mesoporous silica, SBA-15, which contains a hexagonal array of cylindrical pores with tunable diameter, have shown that geometric properties, such as pore surface curvature, and physicochemical properties, such as electric charge and hydrophobicity, play a significant role in the stability of the confined protein²and that these effects differ from proteins immobilized on the external surface of nanoparticles. High surface curvature, in particular, was shown to have a dramatic stabilization effect for the model proteins. This stabilization was most evident when comparing the secondary structure and extraordinary enzymatic activity of the confined protein samples. Expanding on these results, we have studied the structural and packing effects of curvature using the SBA-15 immobilized myoglobin and lysozyme model proteins with small angle neutron scattering. Additionally, we investigate these model proteins while confined in mesoporous materials with different pore network topologies and pore morphology, with a focus on enzymatic activity, loading capacity, and structural changes.

References:

1. Siefker J, Karande P, Coppens M-O. Packaging Biological Cargoes in Mesoporous Materials: Opportunities for Drug Delivery. Expert Opin Drug Deliv. 2014 Nov;11(11):1781-93
2. Sang L-C, Coppens M-O. Effects of surface curvature and surface chemistry on the structure and activity of proteins adsorbed in nanopores. Phys Chem Chem Phys. 2011;13(14):6689