Studying natural structural protein fibers by solid‐state nuclear magnetic resonance

Abstract

As a consequence of evolutionary pressure, various organisms have developed structural fibers displaying a range of exceptional mechanical properties adapted specifically to their functions. An understanding of these properties at the molecular level requires a detailed description of local structure, orientation with respect to the fiber and size of constitutive units, and dynamics on various timescales. The size and lack of long-range order in these protein systems constitute an important challenge to classical structural techniques such as high-resolution NMR and X-ray diffraction. Solidstate NMR overcomes these constraints and is uniquely suited to the study of these inherently disordered systems. Solid-state NMR experiments developed or applied to determine structure, orientation, and dynamics of these complex proteins will be reviewed and illustrated through examples of their applications to fibers such as spider and silkworm silks, collagen, elastin, and keratin.

Retinal dynamics during light activation of rhodopsin revealed by solid-state NMR spectroscopy

“…Even in the presence of considerable molecular motion, it is possible for residual anisotropies to exist as in the case of liquid crystals [81–83]. As a result, the magnetic or electrical interactions in NMR spectroscopy provide a rich source of information about structure and dynamics for membrane proteins [21, 84–94] and peptides [95–103], lipid bilayers [104–108], biopolymer fibers [109, 110], amyloid fibrils [111–118], and inclusion bodies [119]. …”

Secondary Structure Adopted by the Gly-Gly-X Repetitive Regions of Dragline Spider Silk

“…Hence, the next step is to determine the molecular secondary structure and dynamics of these sequenced proteins in spider dragline silk. Protein structural elucidation experimental tools such as nuclear magnetic resonance (NMR) spectroscopy and X-ray Diffraction (XRD) have been extensively used to probe the secondary structures of the proteins that make-up spider dragline silk [7,8,9,10,11,12,13,14,15]. They have provided many insights into the molecular structure and organization of the silk proteins.…”

Determination of isotopic labeling of proteins by precursor ion scanning liquid chromatography/tandem mass spectrometry of derivatized amino acids applied to nuclear magnetic resonance studies

“…Protein fibers such as silk, collagen or mussel byssal threads are complex biopolymers which have unique mechanical properties exquisitely tuned to the tasks that they perform. [1,2] These macroscopic properties are a consequence of the structure of these proteins at a molecular level. It is thus desirable to unravel their structure in order to produce bioinspired synthetic materials, which can be achieved using solid-state nuclear magnetic resonance (SS-NMR).…”