Absolute Intramolecular Distance Measurements with Angstrom-Resolution Using Anomalous Small-Angle X-ray Scattering

Zettl, Thomas; Mathew, Rebecca S.; Seifer, Sönke; Doniach, Sebastian; Harbury, Pehr A. B. and Lipfert, Jan (2016): Absolute Intramolecular Distance Measurements with Angstrom-Resolution Using Anomalous Small-Angle X-ray Scattering. In: Nano Letters, Vol. 16, No. 9: pp. 5353-5357

Abstract

Accurate determination of molecular distances is fundamental to understanding the structure, dynamics, and conformational ensembles of biological macro-molecules. Here we present a method to determine the full,distance,distribution between small (similar to 7 angstrom radius) gold labels attached to macromolecules with very high-precision(<= 1 angstrom) and on an absolute distance scale.,Our method uses anomalous small-angle X-ray scattering close to a gold absorption edge to separate the gold-gold interference pattern from other scattering contributions. Results for 10-30 bp DNA constructs achieve excellent signal-to-noise and are in good agreement with previous results obtained by single-energy,SAXS measurements without requiring the preparation and measurement of single labeled and unlabeled samples. The use of small gold labels in combination with ASAXS read out provides an attractive approach to determining molecular distance distributions that will be applicable to a broad range of macromolecular systems.

• Item Type: Journal article
• Faculties: Physics
• Subjects: 500 Science > 530 Physics
• ISSN: 1530-6984
• Language: English