Carbohydrate-receptor interactions are an integral part of biological events. They play an important role in many cellular processes, such as cell-cell adhesion, cell differentiation and in-cell signaling. Carbohydrates can interact with a receptor by using several types of intermolecular interactions. One of the most important is the interaction of a carbohydrate's apolar part with aromatic amino acid residues, known as dispersion interaction or CH/π interaction. In the study presented here, we attempted for the first time to quantify how the CH/π interaction contributes to a more general carbohydrate-protein interaction. We used a combined experimental approach, creating single and double point mutants with high level computational methods, and applied both to Ralstonia solanacearum (RSL) lectin complexes with α-L-Me-fucoside. Experimentally measured binding affinities were compared with computed carbohydrate-aromatic amino acid residue interaction energies. Experimental binding affinities for the RSL wild type, phenylalanine and alanine mutants were -8.5, -7.1 and -4.1 kcal x mol(-1), respectively. These affinities agree with the computed dispersion interaction energy between carbohydrate and aromatic amino acid residues for RSL wild type and phenylalanine, with values -8.8, -7.9 kcal x mol(-1), excluding the alanine mutant where the interaction energy was -0.9 kcal x mol(-1). Molecular dynamics simulations show that discrepancy can be caused by creation of a new hydrogen bond between the α-L-Me-fucoside and RSL. Observed results suggest that in this and similar cases the carbohydrate-receptor interaction can be driven mainly by a dispersion interaction.
- MeSH
- aminokyseliny aromatické chemie genetika metabolismus MeSH
- bakteriální proteiny chemie genetika metabolismus MeSH
- fukosa chemie metabolismus MeSH
- konformace proteinů MeSH
- konformace sacharidů MeSH
- krystalografie rentgenová MeSH
- lektiny chemie genetika metabolismus MeSH
- molekulární modely * MeSH
- mutace MeSH
- proteiny chemie genetika metabolismus MeSH
- Ralstonia solanacearum genetika metabolismus MeSH
- sacharidy chemie MeSH
- sekundární struktura proteinů MeSH
- terciární struktura proteinů MeSH
- termodynamika MeSH
- vazba proteinů MeSH
- vazebná místa MeSH
- vodíková vazba MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The effect of terminal GLY114* deletion on the binding affinity of the PA-IIL lectin toward L: -fucose was investigated. Both experimental (isothermal titration calorimetry) and computational (molecular dynamics simulations) methods have shown that the deletion mutation decreases the L-fucose affinity. It implies that the PA-IIL saccharide binding affinity is influenced by the dimerization of the lectin. A detailed analysis of computational data confirms the key role of electrostatic interactions in the PA-IIL/saccharide binding.
- MeSH
- bakteriální adheziny genetika chemie metabolismus MeSH
- Escherichia coli genetika MeSH
- financování organizované MeSH
- fukosa chemie metabolismus MeSH
- kalorimetrie metody MeSH
- kinetika MeSH
- kompetitivní vazba MeSH
- krystalizace MeSH
- kvarterní struktura proteinů MeSH
- lektiny genetika chemie metabolismus MeSH
- molekulární modely MeSH
- multimerizace proteinu MeSH
- mutace MeSH
- počítačová simulace MeSH
- Pseudomonas aeruginosa genetika metabolismus MeSH
- rekombinantní proteiny chemie metabolismus MeSH
- sekvenční delece MeSH
- terciární struktura proteinů MeSH
- termodynamika MeSH
- vazba proteinů MeSH
