US-SOMO HPLC-SAXS module: Dealing with capillary fouling and extraction of pure component patterns from poorly resolved SEC-SAXS data

Emre H Brookes, Patrice Vachette, Mattia Rocco, Javier Pérez

Research output: Contribution to journalArticle

29 Scopus citations

Abstract

Size-exclusion chromatography coupled with SAXS (small-Angle X-ray scattering), often performed using a flow-Through capillary, should allow direct collection of monodisperse sample data. However, capillary fouling issues and non-baseline-resolved peaks can hamper its efficacy. The UltraScan solution modeler (US-SOMO) HPLC-SAXS (high-performance liquid chromatography coupled with SAXS) module provides a comprehensive framework to analyze such data, starting with a simple linear baseline correction and symmetrical Gaussian decomposition tools [Brookes, Pérez, Cardinali, Profumo, Vachette & Rocco (2013). J. Appl. Cryst.46, 1823-1833]. In addition to several new features, substantial improvements to both routines have now been implemented, comprising the evaluation of outcomes by advanced statistical tools. The novel integral baseline-correction procedure is based on the more sound assumption that the effect of capillary fouling on scattering increases monotonically with the intensity scattered by the material within the X-ray beam. Overlapping peaks, often skewed because of sample interaction with the column matrix, can now be accurately decomposed using non-symmetrical modified Gaussian functions. As an example, the case of a polydisperse solution of aldolase is analyzed: from heavily convoluted peaks, individual SAXS profiles of tetramers, octamers and dodecamers are extracted and reliably modeled.The US-SOMO HPLC-SAXS (high-performance liquid chromatography coupled with small-Angle X-ray scattering) module is an advanced tool for the comprehensive analysis of SEC-SAXS (size-exclusion chromatography coupled with SAXS) data. It includes baseline and band-broadening correction routines, and Gaussian decomposition of overlapping skewed peaks into pure components.

Original languageEnglish (US)
Pages (from-to)1827-1841
Number of pages15
JournalJournal of Applied Crystallography
Volume49
Issue number5
DOIs
StatePublished - Oct 1 2016

    Fingerprint

Keywords

  • aldolase supramolecular complexes
  • asymmetric modified Gaussian decomposition
  • CorMap analysis
  • multi-resolution modeling
  • P-value analysis
  • poorly resolved chromatographic peaks
  • US-SOMO HPLC-SAXS module

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

Cite this