Open AccessRöntgenkleinwinkel‐Untersuchungen an der Fettsäuresynthetase aus Hefe
Author(s) -
Pilz I.,
Herbst M.,
Kratky O.,
Oesterhelt D.,
Lynen F.
Publication year - 1970
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1970.tb00898.x
Subject(s) - radius , chemistry , scattering , ellipsoid , volume (thermodynamics) , spheres , shell (structure) , fatty acid , crystallography , thermodynamics , physics , materials science , biochemistry , optics , computer security , astronomy , computer science , composite material
Fatty acid synthetase, a multienzyme complex from yeast, was analysed by small angle x‐ray scattering. The molecular weight determined by this method (2.2 × 10 6 ) was in close agreement with the value determined earlier by ultracentrifugation. The experimental data indicate that the complex is contained in a ellipsoid volume with axial ratios 1:1:1.2. The relationship of radius of gryation to volume and the height of the second maximum in the scattering curve suggest that the complex proteins enclose a hollow space. A model is proposed where the theoretical scattering curve closely aggrees with the curve measured for the fatty acid synthetase. The model consists of a spherical shell, composed of spheres, having an average wall thickness of 20 Å and divided in half by a planar wall also 20 Å thick. The outer radius is 125 Å. On the basis of this model the catalysis of fatty acid synthesis by the synthestase is discussed.