Thermodynamic and structural analysis of interactions between peptide ligands and SEB.
Staphylococcal enterotoxin B (SEB) is an exotoxin produced by Staphylococcus aureus and commonly associated with food poisoning. In this study, SEB-binding peptides were identified by screening a phage displayed peptide library. The binding of peptides to SEB was tested with isothermal titration calorimetry (ITC) and of the five selected peptides, three showed affinity to SEB, with one measured to have the highest affinity constant (10(5) M(-1)). ITC revealed that the interaction of peptide ligands with SEB was driven entropically and the binding was dominated by hydrophobic interactions. Circular dichroism (CD) measurements and molecular dynamics (MD) simulations, together, give a structural insight into the interaction of peptides with SEB. While SEB binding peptides showed random coil structure before binding, after complex formation they had more ordered structures. The peptide with highest affinity to SEB showed stable conformation during MD simulation. Taken together, our approach about thermodynamic and structural characterization of peptide ligands can be used to develop aptamers, with high affinity and selectivity, for biosensor applications.
Dudak
Fahriye Ceyda
FC
Department of Food Engineering, Hacettepe University, Beytepe 06800, Ankara, Turkey.
Soykut
Esra Acar
EA
Oğuz
Murat Erman
ME
Yaşar
Fatih
F
Boyaci
Ismail Hakki
IH
D002151:Calorimetry; D002942:Circular Dichroism; D004768:Enterotoxins / Q000378:metabolism*; D056004:Molecular Dynamics Simulation; D019151:Peptide Library; D010455:Peptides / Q000378:metabolism*; D011485:Protein Binding; D013816:Thermodynamics
D004768:Enterotoxins; D019151:Peptide Library; D010455:Peptides; C031818:enterotoxin B, staphylococcal