title: Binding analysis between L-histidine immobilized and oligonucleotides by SPR and NMR.
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.
authors: CICS-UBI - Centro de Investigação em Ciências da Saúde, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal. carlacruz@fcsaude.ubi.pt
authors: Carla
authors: C
authors: Cruz
authors: Sandra D
authors: SD
authors: Santos
authors: Eurico J
authors: EJ
authors: Cabrita
authors: João A
authors: JA
authors: Queiroz
mesh_terms: D006639:Histidine / Q000737:chemistry*; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D009841:Oligonucleotides / Q000737:chemistry*; D012685:Sepharose / Q000737:chemistry; D020349:Surface Plasmon Resonance
chemical_list: D009841:Oligonucleotides; D006639:Histidine; D012685:Sepharose