A two-dimensional spin-diffusion NMR study on the local structure of a water-soluble model peptide for Nephila clavipes dragline silk (MaSp1) before and after spinning

Abstract

The local structure of the acidic-treated model peptides,(E)8GGLGGQGAG(A)6GGAGQGGYGG, derived from the consensus sequence of Nephila clavipes fibroin major ampullate spidroin 1 was determined using two-dimensional proton-driven spin-diffusion solid-state NMR under off-magic-angle spinning coupled with 13C isotope double labeling of specific residues. We observed a positional dependence on the torsion angles of Ala residues in the β sheet. Torsion angle of the Ala residue at the center of poly-Ala domain concentrates around at (ϕ, ψ) = (−150°, 150°), while that of its periphery is distorted and more distributed.