Rapid Screening of DNA-Ligand Complexes via 2D-IR Spectroscopy and ANOVA-PCA

Anal Chem. 2018 Feb 20;90(4):2732-2740. doi: 10.1021/acs.analchem.7b04727. Epub 2018 Feb 6.

Abstract

Two-dimensional infrared spectroscopy (2D-IR) is well established as a specialized, high-end technique for measuring structural and solvation dynamics of biological molecules. Recent technological developments now make it possible to acquire time-resolved 2D-IR spectra within seconds, and this opens up the possibility of screening-type applications comparing spectra spanning multiple samples. However, such applications bring new challenges associated with finding accurate, efficient methodologies to analyze large data sets in a timely, informative manner. Here, we demonstrate such an application by screening 2016 2D-IR spectra of 12 double-stranded DNA oligonucleotides obtained in the presence and absence of binding therapeutic molecule Hoechst 33258. By applying analysis of variance combined with principal component analysis (ANOVA-PCA) to 2D-IR data for the first time, we demonstrate the ability to efficiently retrieve the base composition of a DNA sequence and discriminate ligand-DNA complexes from unbound sequences. We further show accurate differentiation of the induced-fit and rigid-body binding modes that is key to identifying optimal binding interactions of Hoechst 33258, while ANOVA-PCA results across the full sequence range correlate directly with thermodynamic indicators of ligand-binding strength that require significantly longer data acquisition times to obtain.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • DNA / chemistry*
  • Ligands
  • Principal Component Analysis*
  • Spectrophotometry, Infrared

Substances

  • Ligands
  • DNA