Intermolecular Packing in B. mori Silk Fibroin: Multinuclear NMR Study of the Model Peptide (Ala-Gly)15 Defines a Heterogeneous Antiparallel Antipolar Mode of Assembly in the Silk II Form

被引：45

作者：

Asakura, Tetsuo ^{[1
,2
]}

Ohata, Takuya ^{[1
]}

Kametani, Shunsuke ^{[3
]}

Okushita, Keiko ^{[1
]}

Yazawa, Koji ^{[4
]}

Nishiyama, Yusuke ^{[4
]}

Nishimura, Katsuyuki ^{[2
]}

Aoki, Akihiro ^{[1
]}

Suzuki, Furitsu ^{[5
]}

Kaji, Hironori ^{[5
]}

Ulrich, Anne S. ^{[6
,7
]}

Williamson, Mike P. ^{[8
]}

机构：

[1] Tokyo Univ Agr & Technol, Dept Biotechnol, Koganei, Tokyo 1848588, Japan

[2] Inst Mol Sci, Okazaki, Aichi 4448585, Japan

[3] Mitsui Chem Anal & Consulting Serv Inc, Sodegaura, Chiba 2990265, Japan

[4] JEOL RESONANCE Inc, Akishima, Tokyo 1968558, Japan

[5] Kyoto Univ, Inst Chem Res, Uji, Kyoto 6110011, Japan

[6] Karlsruhe Inst Technol, IBG2, D-76131 Karlsruhe, Germany

[7] Karlsruhe Inst Technol, IOC, D-76131 Karlsruhe, Germany

[8] Univ Sheffield, Dept Mol Biol & Biotechnol, Sheffield S10 2TN, S Yorkshire, England

来源：

MACROMOLECULES | 2015年 / 48卷 / 01期

关键词：

SOLID-STATE NMR; ACCURATE H-1 POSITIONS; BETA-TURN STRUCTURE; C-13; NMR; CHEMICAL-SHIFTS; STRUCTURAL-ANALYSIS; CRYSTAL-STRUCTURES; SPIN-DIFFUSION; DOUBLE-QUANTUM; COMPUTATION;

D O I：

10.1021/ma502191g

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

摘要：

We have previously suggested that crystalline Bombyx mori silk in silk II form (the silk structure after spinning) is not a simple antiparallel beta-sheet but is intrinsically heterogeneous. Using the peptide (AG)(15), we have obtained the first fully assigned high resolution solid state H-1 NMR spectrum. Distinct heterogeneity was observed, in both H-1 and C-13 CP/MAS signals. Based on these results, a new model is proposed that contains two different packing arrangements of antiparallel beta-sheets. The structures were energetically minimized by CASTEP calculation and used to calculate the solid state H-1, C-13, and N-15 NMR chemical shifts using the GIPAW method. This new model was supported by good agreement between the calculated and observed H-1, C-13, and N-15 chemical shifts and relative (HH)-H-1-H-1 proximities obtained from 2D H-1 DQMAS experiments. We conclude that the intermolecular packing of B. mori silk fibroin has been finally resolved.

引用

页码：28 / 36

页数：9

共 46 条

[1] Refinement of repeated β-turn structure for silk I conformation of Bombyx mori silk fibroin using 13C solid-state NMR and X-ray diffraction methods [J].