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Heterogeneous exchange behavior of Samia cynthia ricini silk fibroin during helix–coil transition studied with 13 C NMR
Author(s) -
Nakazawa Yasumoto,
Asakura Tetsuo
Publication year - 2002
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(02)03332-x
Subject(s) - fibroin , alanine , tripeptide , helix (gastropod) , residue (chemistry) , silk , chemistry , crystallography , random coil , glycine , nuclear magnetic resonance spectroscopy , chemical shift , stereochemistry , nuclear magnetic resonance , circular dichroism , amino acid , materials science , organic chemistry , biochemistry , biology , physics , ecology , snail , composite material
The structure and structural transition of the glycine residue adjacent to the N‐terminal alanine residue of the poly( L ‐alanine), (Ala) 12–13 , region in Samia cynthia ricini silk fibroin was studied using 13 C nuclear magnetic resonance (NMR). Most of the glycine carbonyl peaks in the 13 C solution NMR spectrum of [1‐ 13 C]glycine‐silk fibroin could be assigned to the primary structure from the comparison of the 13 C chemical shifts of seven glycine‐containing tripeptides. The slow exchange between helix and coil forms in the NMR time scale was observed with increasing temperature exclusively for the underlined glycine residue in the Gly‐ ‐(Ala) 12–13 sequence during fast helix–coil transition of the (Ala) 12–13 region.