Transferred NOESY NMR studies of biotin mimetic peptide (FSHPQNT) bound to streptavidin: A structural model for studies of peptide-protein interactions.

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Transferred NOESY NMR studies of biotin mimetic peptide (FSHPQNT) bound to streptavidin: A structural model for studies of peptide-protein interactions.

Transferred NOESY NMR studies of biotin mimetic peptide (FSHPQNT) bound to streptavidin: A structural model for studies of peptide-protein interactions.

Chem Biol Drug Des. 2011 Feb 5;

Authors: Gizachew D, Dratz E

Protein-protein interactions control signaling, specific adhesion and many other biological functions. The three dimensional structures of the interfaces and bound ligand can be approached with Tr-NOESY NMR, which can be applied to much larger proteins than conventional NMR and requires less concentrated protein. However, it is not clear how accurately the structures of protein-bound peptides can be determined by Tr-NOESY. We studied the structure of a biotin-mimetic peptide (FSHPQNT) bound to streptavidin, since the x-ray structure of the complex is available to 1.74Å resolution and we found that conditions could be adjusted so that the off-rates were fast enough for Tr-NOESY NMR. The off-rate was determined with (19) F NMR, using a para-fluoro-phenylalanine analog of the peptide. A new criterion for a lower limit on kinetic off-rate was found, which allowed accurate structure determination at a slower off-rate. Non-specific binding of the peptide to streptavidin was not significant, since biotin blocked the peptide Tr-NOESY. Protein mediation for the long range peptide Tr-NOESY cross-peaks was corrected by a Tr-NOESY/ROESY averaging procedure. The protein-bound structure of the peptide was determined by Tr-NOESY constrained and simulated annealing. The structure deduced from the NMR was close to the x-ray structure.

PMID: 21294848 [PubMed - as supplied by publisher]



Source: PubMed