Small angle X-ray scattering of wheat seed-storage proteins: α-, γ- and ω-gliadins and the high molecular weight (HMW) subunits of glutenin

Aim. The aim of the research was to study common wheat material developed from crosses with Aegilops biuncialis Vis. using storage protein loci as markers for chromosome 1U. Methods. SDS and APAG electrophoreses of seed storage proteins were employed to identify alleles at the Glu-1 and Gli-1 loci. The following markers of chromosome 1U of Ae. biuncialis were used: the Glu-U1 locus encoding high-molecular-weight glutenin subunits located on the long arm (1UL) and the gliadin locus Gli-U1 on the short arm (1US). Results. In F6–F7, elimination of chromosome 1U material with a frequency of about 0.222 proceeded. This indicates selection against unbalanced genotypes, which could be tracked using markers for chromosome 1U. In wheat F4–F6 hybrids from crosses with Ae. biuncialis, we revealed a high frequency of formation of genotypes possessing the 1UL arm and lacking 1US. Conclusions. Since the Glu-U1 locus on the arm 1UL encodes high-molecular-weight subunits which directly determine bread-making quality, the developed wheat material is a source of a new allele of this locus introgressed from Ae. biuncialis for enriching the common wheat gene pool. Keywords: Triticum aestivum, Aegilops biuncialis, storage proteins, introgression.

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Glucose isomerase from Streptomyces rubiginosus – potential molecular weight standard for small-angle X-ray scattering

Journal of Applied Crystallography ◽

10.1107/s0021889805010472 ◽

2005 ◽

Vol 38 (3) ◽

pp. 555-558 ◽

Cited By ~ 38

Author(s):

Maciej Kozak

Keyword(s):

Molecular Weight ◽

Synchrotron Radiation ◽

Small Angle ◽

Glucose Isomerase ◽

Radius Of Gyration ◽

X Ray ◽

X Ray Scattering ◽

Streptomyces Rubiginosus ◽

Molecular Weight Standard ◽

Ray Scattering

Stability of solutions of glucose isomerase from Streptomyces rubiginosus on long-term storage and on exposure to synchrotron radiation has been studied by the small-angle X-ray scattering (SAXS) method. The values of the radii of gyration and forward scattering do not change significantly on storage and on exposure to synchrotron radiation. The mean value of the radius of gyration characterizing glucose isomerase is R G = 3.27 ± 0.02 nm. For comparison, a SAXS study of monodispersive and aggregated bovine serum albumin (BSA) has been carried out. The results show that glucose isomerase could be a more stable molecular weight standard for SAXS than BSA.

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Performance on absolute scattering intensity calibration and protein molecular weight determination at BL16B1, a dedicated SAXS beamline at SSRF

Journal of Synchrotron Radiation ◽

10.1107/s1600577516019135 ◽

2017 ◽

Vol 24 (2) ◽

pp. 509-520 ◽

Cited By ~ 38

Author(s):

Jianrong Zeng ◽

Fenggang Bian ◽

Jie Wang ◽

Xiuhong Li ◽

Yuzhu Wang ◽

...

Keyword(s):

Molecular Weight ◽

Small Angle ◽

Absolute Intensity ◽

Molecular Weight Determination ◽

X Ray ◽

X Ray Scattering ◽

Saxs Intensity ◽

The Absolute ◽

Intensity Calibration ◽

Ray Scattering

The optical system and end-station of bending-magnet beamline BL16B1, dedicated to small-angle X-ray scattering (SAXS) at the Shanghai Synchrotron Radiation Facility, is described. Constructed in 2009 and upgraded in 2013, this beamline has been open to users since May 2009 and supports methodologies including SAXS, wide-angle X-ray scattering (WAXS), simultaneous SAXS/WAXS, grazing-incidence small-angle X-ray scattering (GISAXS) and anomalous small-angle X-ray scattering (ASAXS). Considering that an increasing necessity for absolute calibration of SAXS intensity has been recognized in in-depth investigations, SAXS intensity is re-stated according to the extent of data processing, and the absolute intensity is suggested to be a unified presentation of SAXS data in this article. Theory with a practical procedure for absolute intensity calibration is established based on BL16B1, using glass carbon and water as primary and secondary standards, respectively. The calibration procedure can be completed in minutes and shows good reliability under different conditions. An empirical line of scale factor estimation is also established for any specific SAXS setup at the beamline. Beamline performance on molecular weight (MW) determination is provided as a straightforward application and verification of the absolute intensity calibration. Results show good accuracy with a deviation of less than 10% compared with the known value, which is also the best attainable accuracy in recent studies using SAXS to measure protein MW. Fast MW measurement following the demonstrated method also enables an instant check or pre-diagnosis of the SAXS performance to improve the data acquisition.

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