Alignment of filamentous proteins and associated molecules through confinement in microchannels

Abstract

A technique has been developed to study the structure and interaction of aligned filamentous proteins by confining them in surface-treated silicon microchannels. The micron-size channels induce the semiflexible biopolymers with comparable or larger persistence lengths than the channel width to naturally align parallel to the channel in solution, which facilitates structural studies by x-ray diffraction and optical imaging techniques. As a model system, we investigated the cross-linking of filamentous actin (F-actin) with the bundling protein α-actinin in the microchannels. Synchrotron x-ray diffraction and fluorescence microscopy were used to confirm that F-actin, when bundled in the device, conforms to the alignment of the channel geometry.