Evidence from 13C solid-state NMR spectroscopy for a lamella structure in an alanine-glycine copolypeptide: a model for the crystalline domain of Bombyx mori silk fiber.
13C high-resolution solid-state NMR coupled with selective 13C isotope-labeling of different Ala one methyl carbons was used to clarify the structure of (AG)15 peptide in the silk II structure as a model for the crystalline domain of Bombyx mori silk fiber. At the inner part of the peptide, the fraction of the peak at 16.6 ppm of the Ala Cbeta resonance assigned to beta-turn structure increased at 11th and 19th positions. These data indicate the appearance of the most probable lamellar structure having a turn structure at these two positions, although the position of turn was distributed along the chain.
Asakura
Tetsuo
T
Department of Biotechnology, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan. asakura@cc.tuat.ac.jp
Nakazawa
Yasumoto
Y
Ohnishi
Erika
E
Moro
Fumika
F
D000409:Alanine / Q000737:chemistry*; D000818:Animals; D012831:Bombyx / Q000737:chemistry*; D002247:Carbon Isotopes / Q000737:chemistry; D005998:Glycine / Q000737:chemistry*; D019476:Insect Proteins / Q000737:chemistry*; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D010455:Peptides / Q000737:chemistry*; D017433:Protein Structure, Secondary; D047011:Silk / Q000737:chemistry*
D002247:Carbon Isotopes; D019476:Insect Proteins; D010455:Peptides; D047011:Silk; D000409:Alanine; D005998:Glycine