Precipitantless Crystallization of Protein Molecules Induced by High Surface Potential

Abstract

In the context of protein crystallization, surface decorated with heterogeneous topographical features decreases the energy barrier for nucleation, thereby facilitating crystallization; a precipitant is, nevertheless, required to be used. Here we eliminate the need of such precipitant by using a combined effect of nanoscopic surface undulations and charges on a substrate. Using surface instabilities as a tool for generating such features on polymeric materials, we show that intrinsic curvature of nanofeatures (<10 nm) coupled with surface charges lead to spatial gradient in potential as high as 140 V·μm–1, where curvature gets maximum. These surfaces show remarkable ability to induce nucleation not achieved by any other conventional process. They induce precipitantless nucleation of proteins, directed crystallization of a specific protein from a mixture of two or more species, and even simultaneous crystallization from a mixture of proteins. These results signify large scale molecular ordering at the bulk...