Shape and quaternary structure of alpha-globulin from sesame (Sesamum indicum L.) seed as revealed by small angle x-ray scattering and quasi-elastic light scattering.

The alpha-globulin from sesame seed has a molar mass of 2.7 X 10(5) g mol-1, determined by x-ray scattering, and (2.8 +/- 0.3) 10(5) g mol-1, determined by quasi-elastic light scattering. The radius of gyration RG amounts to (4.1 +/- 0.1) nm and (3.9 +/- 0.2) nm as determined by Guinier approximation and from the distribution function D(x), respectively. The molecule has a Stokes radius Rs of (5.4 +/- 0.15) nm and a maximum dimension L of (11 less than L less than 15) nm. The translational diffusion coefficient D0(20),w and the ratio of fractional coefficients f/fmin amount to (3.95 +/- 0.12) X 10(-7) cm2 s-1 and 1.25, respectively. The quaternary structure of the protein molecule is approximated by a model consisting of six spherical subunits situated at the vertices of an octahedron having the symmetry 32.

Shape, symmetry, hydration and secondary structure of the legumin from Vicia faba in solution.

The following physical parameters of the legumin from Vicia faba were determined by means of small-angle X-ray scattering, quasi-elastic light scattering and circular dichroism: molar mass, M = 3.5 X 10(5) g/mol; radius of gyration, Rg = 4.45 nm; maximum dimension, L = 13 nm; translational diffusion coefficient, D0(20),w = 3.38 X 10(-7) cm2 X s-1; alpha-helix content about 15%; content of beta-sheets 10%; dihedral point group symmetry of the molecule 32.

[Analysis of the quaternary structure of the 11S plant globulins by means of small-angle X-ray scattering]. / Bestimmung der Quartärstruktur der 11 S Pflanzenglobuline mit Hilfe der Rötgen-Kleinwinkelstreuung.

It is demonstrated by means of small-angle X-ray scattering that 11 S globulin of sunflower (Helianthus annuus L.) consists of six subunits. The point group symmetry of the quaternary structure is 23 (D3). It is postulated that this symmetry is typical for the group of 11 S seed proteins.

[Small-angle scattering of the quaternary structure of phosphofructokinase from baker's yeast]. / Röntgen-Kleinwinkelstreuungsuntersuchungen zur Quartärstruktur der Phosphofruktokinase aus Bäckerhefe.

The phosphofructokinase (E.C. 2.7.1.11) from baker's yeast was examined by means of small angle X-ray scattering in 0.1 M K-phosphate buffer, pH 7. A quaternary structure model was obtained from the comparison of the model scattering curve with the experimental one. The eight subunits of the yeast phosphofructokinase are arranged in a D2-symmetry. The proposed scattering equivalent model corresponds to a structural description with a resolution of 2.5 nm. Models with a C8-symmetry and D4-symmetry can be ruled out.