1 research outputs found
Solid-State NMR Structure Determination of Whole Anchoring Threads from the Blue Mussel Mytilus edulis
The molecular structure of the blue mussel Mytilus
edulis whole anchoring threads was studied by two-dimensional <sup>13</sup>C solid-state NMR on fully labeled fibers. This unique material
proves to be well ordered at a molecular level despite its heterogeneous
composition as evidenced by the narrow measured linewidths below 1.5
ppm. The spectra are dominated by residues in collagen environments,
as determined from chemical shift analysis, and a complete two-dimensional
assignment (including minor amino acids) was possible. The best agreement
between predicted and experimental backbone chemical shifts was obtained
for collagen helices with torsion angles (ā75Ā°, +150Ā°).
The abundant glycine and alanine residues can be resolved in up to
five different structural environments. Alanine peaks could be assigned
to collagen triple-helices, Ī²-sheets (parallel and antiparallel),
Ī²-turns, and unordered structures. The use of ATR-FTIR microscopy
confirmed the presence of these structural environments and enabled
their location in the core of the thread (collagen helices and antiparallel
Ī²-sheets) or its cuticle (unordered structures). The approach
should enable characterization at the molecular level of a wide range
of byssus macroscopic properties