Advances in Fiber Diffraction of Macromolecular Assembles

Abstract

X‐ray fiber diffraction is often the only means available to study fibrous macromolecular protein assemblies in their natural context. The structure of complex assemblies such as connective tissues, muscle, and amyloid systems, which may be very sensitive to environmental conditions or to the disassembly required for study by crystallography or nuclear magnetic resonance (NMR), may particularly benefit from a fiber diffraction approach. Even in instances where a fibrous system can be studied straightforwardly with atomistic or microscopic methods, it may benefit from fiber diffraction because of its potential ability to obtain large‐ to small‐scale structural details while maintaining the item of interest in situ within its host tissue, organ, or organism. In this article, we describe recent advances in macromolecular fiber diffraction in the context of its historical significance in this, the hundredth year of X‐ray diffraction of crystalline biological substances. We limit our discussion to cover the advances made in X‐ray sources in terms of experimental benefits to X‐ray imaging and scanning experiments and to technical advances leading to strides in our understanding of biological systems such as collagen, muscle, and amyloid that have evaded definition for much of the last century.