2a7h

Publication Abstract from PubMed

Complete and highly redundant data sets were collected at different wavelengths between 0.80 and 2.65 A for a total of ten different protein and DNA model systems. The magnitude of the anomalous signal-to-noise ratio as assessed by the quotient R(anom)/R(r.i.m.) was found to be influenced by the data-collection wavelength and the nature of the anomalously scattering substructure. By utilizing simple empirical correlations, for instance between the estimated deltaF/F and the expected R(anom) or the data-collection wavelength and the expected R(r.i.m.), the wavelength at which the highest anomalous signal-to-noise ratio can be expected could be estimated even before the experiment. Almost independent of the nature of the anomalously scattering substructure and provided that no elemental X-ray absorption edge is nearby, this optimal wavelength is 2.1 A.

On the routine use of soft X-rays in macromolecular crystallography. Part III. The optimal data-collection wavelength.,Mueller-Dieckmann C, Panjikar S, Tucker PA, Weiss MS Acta Crystallogr D Biol Crystallogr. 2005 Sep;61(Pt 9):1263-72. Epub 2005, Aug 16. PMID:16131760^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.