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Size and shape of the repetitive domain of high molecular weight wheat gluten proteins. I. Small‐angle neutron scattering
Author(s) -
Egelhaaf Stefan U.,
Swieten Eric van,
Bosma Tjibbe,
Boef Esther de,
Dijk Alard A. van,
Robillard George T.
Publication year - 2003
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.10370
Subject(s) - chemistry , cylinder , scattering , small angle x ray scattering , neutron scattering , small angle scattering , gluten , small angle neutron scattering , wheat gluten , crystallography , tropoelastin , flexibility (engineering) , neutron , chemical physics , physics , optics , geometry , nuclear physics , mathematics , biochemistry , statistics , extracellular matrix
The solution structure of the central repetitive domain of high molecular weight (HMW) wheat gluten proteins has been investigated for a range of concentrations and temperatures using mainly small‐angle neutron scattering. A representative part of the repetitive domain (dB1) was studied as well as an “oligomer” basically consisting of four dB1 units, which has a length similar to the complete central domain. The scattering data over the entire angular range of both proteins are in quantitative agreement with a structural model based on a worm‐like chain, a model frequently used in polymer theory. This model describes the “supersecondary structure” of dB1 and dB4 as a semiflexible cylinder with a length of about 235 and 900 Å, respectively, and a cross‐sectional diameter of about 15 Å. The flexibility of both proteins is characterized by a persistence length of about 13 Å. Their structures are thus quantitatively identical, which implies that the central HMW domain can be elongated while retaining its structural characteristics. It seems conceivable that the flexible cylinder results from a helical structure, which resembles the β‐spiral observed in earlier studies on gluten proteins and elastin. However, compared to the previously proposed structure of a (stiff) rod, our experiments clearly indicate flexibility of the cylinder. © 2003 Wiley Periodicals, Inc. Biopolymers 69: 311–324, 2003