Binding analysis between L-histidine immobilized and oligonucleotides by SPR and NMR

Int J Biol Macromol. 2013 May;56:175-80. doi: 10.1016/j.ijbiomac.2013.02.012. Epub 2013 Feb 24.

Abstract

Saturation transfer difference (STD) NMR technique and surface plasmon resonance (SPR) are used to study amino acid affinity supports-nucleotides interactions with L-histidine amino acid immobilized on a surface as model support. We have immobilized L-histidine ligand on a carboxymethyldextran-modified gold surface intended for surface plasmon resonance and we analyze the binding profiles of synthetic polynucleotides (1-6 base, sugar and backbone) by determining the equilibrium dissociation constant (KD). The SPR binding profile (square-shaped) is identical for all the complexes and the highest binding affinity can be found for polyA₆ followed by polyG₆. As expected, the 5'-mononucleotides have the lowest affinity. To further study the structural aspects of the interaction we investigate the polynucleotide binding preferences to L-histidine chromatography support by STD-NMR spectroscopy. These results revealed that an increase in the number of bases and backbone to 6 units leads to more contacts with the support, where the main driving force for the interaction with polynucleotides are through the base, except for polyC₆, which is mainly through sugar-phosphate backbone. Therefore, the combination of SPR measurements with STD-NMR technique allowed to establish fine details of the molecular recognition process involved in amino acid affinity supports-nucleotides complexes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Histidine / chemistry*
  • Kinetics
  • Magnetic Resonance Spectroscopy*
  • Oligonucleotides / chemistry*
  • Sepharose / chemistry
  • Surface Plasmon Resonance*

Substances

  • Oligonucleotides
  • Histidine
  • Sepharose