0000000000007823
AUTHOR
H.b. Stuhrmann
Comparison of neutron and X-ray scattering of dilute myoglobin solutions.
Experimental results obtained by neutron scattering of dilute solutions of myoglobin are compared with those obtained by X-ray scattering. X-ray scattering remains the more powerful technique at wider angles above 0.3 A−1, where neutron experiments are less accurate because of low coherent scattering probability and high incoherent background. Neutron scattering is preferable at momentum transfers below 0.2 A−1; the conditions for applying the contrast variation method for the evaluation of the three basic scattering functions, which are due to shape and internal structure, equation (3), are ideally fulfilled in this region. Furthermore, neutrons allow observation of the hydrogen-deuterium …
Resonant scattering in macromolecular structure research. Applications in molecular biology and material science
Abstract This report concerns the X-ray resonance scattering work carried out using the instrument X15 which receives synchrotron radiation from the storage ring DORIS. X15 covers a wavelength range from 0.6 to 3.3 A. It therefore accesses resonance scattering at the K-absorption edges of the elements with Z = 20 (Ca) to Z = 42 (Mo) and at the L 3 -absorption edges from Z = 50 (Sn) to all heavier atoms. The instrument consists of a double monochromator with a vertical offset of the beam by 1.22 m and a camera of 10 m length. A multiwire proportional chamber (from A. Gabriel) at the end of the evacuated beam line detects the scattered X-ray photons on its area 200 mm × 200 mm. The distances …
Low angle neutron scattering of ferritin studied by contrast variation.
Ferritins containing different amounts of iron have been studied by neutron small angle scattering in H 2 O/D 2 O mixtures. Apoferritin has also been studied in solutions of small organic molecules. There is a larger contrast variation in the solutions of small organic molecules than in the corresponding H 2 O/D 2 O experiments from which it may be calculated that I g of apoferritin contains 0·3 g of H 2 O. The solvent composition at zero contrast varies regularly with the iron content of the protein: there is evidence for polydispersity in the iron content of the ferritin used. From analysis of the scattering curves it is concluded that the iron is probably not homogeneously distributed in…