Determination of binding capacity and adsorption enthalpy between Human Glutamate Receptor (GluR1) peptide fragments and kynurenic acid by surface plasmon resonance experiments

E Csapó; Z Majláth; Á Juhász; B Roósz; A Hetényi; G K Tóth; J Tajti; L Vécsei; I Dékány

doi:10.1016/j.colsurfb.2014.10.046

Determination of binding capacity and adsorption enthalpy between Human Glutamate Receptor (GluR1) peptide fragments and kynurenic acid by surface plasmon resonance experiments

Colloids Surf B Biointerfaces. 2014 Nov 1:123:924-9. doi: 10.1016/j.colsurfb.2014.10.046. Epub 2014 Oct 30.

Authors

E Csapó¹, Z Majláth², Á Juhász¹, B Roósz³, A Hetényi⁴, G K Tóth⁴, J Tajti², L Vécsei⁵, I Dékány⁶

Affiliations

¹ MTA-SZTE Supramolecular and Nanostructured Materials Research Group, University of Szeged, H-6720 Dóm tér 8, Szeged, Hungary.
² Department of Neurology, University of Szeged, H-6725 Semmelweis u. 6, Szeged, Hungary.
³ Department of Chemistry and Chemical Informatics, University of Szeged, Juhász Gyula Faculty of Education, H-6725 Boldogasszony sgt. 6, Szeged, Hungary.
⁴ Department of Medical Chemistry, Faculty of Medicine, University of Szeged, H-6720 Dóm tér 8, Szeged, Hungary.
⁵ Department of Neurology, University of Szeged, H-6725 Semmelweis u. 6, Szeged, Hungary; MTA-SZTE Neuroscience Research Group, University of Szeged, H-6725 Semmelweis u. 6, Szeged, Hungary.
⁶ MTA-SZTE Supramolecular and Nanostructured Materials Research Group, University of Szeged, H-6720 Dóm tér 8, Szeged, Hungary; Department of Medical Chemistry, Faculty of Medicine, University of Szeged, H-6720 Dóm tér 8, Szeged, Hungary. Electronic address: i.dekany@chem.u-szeged.hu.

PMID: 25466458
DOI: 10.1016/j.colsurfb.2014.10.046

Abstract

The interaction between kynurenic acid (KYNA) and two peptide fragments (ca. 30 residues) of Human Glutamate Receptor 201-300 (GluR1) using surface plasmon resonance (SPR) spectroscopy was investigated. Because of the medical interest in the neuroscience, GluR1 is one of the important subunits of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPAR). AMPARs are ionotoropic glutamate receptors, which are mediating fast synaptic transmission and are crucial for plasticity in the brain. On the other hand, KYNA has been suggested to have neuroprotective activity and it has been considered for apply in therapy in certain neurobiological disorders. In this article the adsorption of the GluR1201-230 and GluR1231-259 peptides were studied on gold biosensor chip. The peptides were chemically bonded onto the gold surface via thiol group of L-cysteine resulted in the formation of peptide monolayer on the SPR chip surface. Because the GluR1231-259 peptide does not contain L-cysteine the Val256 was replaced by Cys256. The cross sectional area and the surface orientation of the studied peptides were determined by SPR and theoretical calculations (LOMETS) as well. The binding capability of KYNA on the peptide monolayer was studied in the concentration range of 0.1-5.0 mM using 150 mM NaCl ionic strength at pH 7.4 (±0.02) in phosphate buffer solutions. In order to determine the binding enthalpy the experiments were carried out between +10°C and +40°C. The heat of adsorption was calculated by using adsorption isotherms at different surface loading of KYNA on the SPR chip.

Keywords: AMPA receptor; Adsorption; Enthalpy; GluR1; Kynurenic acid.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adsorption
Humans
Kynurenic Acid / chemistry*
Peptide Fragments / chemistry*
Protein Binding
Receptors, Glutamate / chemistry*
Surface Plasmon Resonance / methods*

Substances

Peptide Fragments
Receptors, Glutamate
Kynurenic Acid