Characterizing the Space of interatomic Distance Distribution Functions Consistent with Solution Scattering Data

: Scattering of neutrons and x-rays from molecules in solution offers alternative approaches to the studying of a wide range of macromolecular structures in their solution state without the need of crystallization. In this paper, we study one part of the problem of elucidating three-dimensional structure from solution scattering data, determining the distribution of interatomic distances, P(r). This problem is known to be ill-conditioned; for a single observed diffraction pattern, there may be many consistent distance distribution functions. Due to the ill conditioning, there is a risk of overfitting the observed scattering data. We propose a new approach to avoiding this problem, accepting the validity of multiple alternative P(r) curves rather than seeking a single “best”. We show that there are linear constraints that ensure that a computed P(r) is consistent with the experimental data. The constraints enforce smoothness in the P(r) curve, ensure that the P(r) curve is a prob...

• Type: Journal
• Year: 2010
• Where: JBCB
• Authors: Paritosh A. Kavathekar, Bruce A. Craig, Alan M. Friedman, Chris Bailey-Kellogg, Devin J. Balkcom
• Keywords: JBCB 2010, Observed Scattering Data, Reference Curves, Scattering