Stability of Ligand-induced Protein Conformation Influences Affinity in Maltose-binding Protein.
J Mol Biol
; 433(15): 167036, 2021 07 23.
Article
in En
| MEDLINE
| ID: mdl-33957147
ABSTRACT
Our understanding of what determines ligand affinity of proteins is poor, even with high-resolution structures available. Both the non-covalent ligand-protein interactions and the relative free energies of available conformations contribute to the affinity of a protein for a ligand. Distant, non-binding site residues can influence the ligand affinity by altering the free energy difference between a ligand-free and ligand-bound conformation. Our hypothesis is that when different ligands induce distinct ligand-bound conformations, it should be possible to tweak their affinities by changing the free energies of the available conformations. We tested this idea for the maltose-binding protein (MBP) from Escherichia coli. We used single-molecule Förster resonance energy transfer (smFRET) to distinguish several unique ligand-bound conformations of MBP. We engineered mutations, distant from the binding site, to affect the stabilities of different ligand-bound conformations. We show that ligand affinity can indeed be altered in a conformation-dependent manner. Our studies provide a framework for the tuning of ligand affinity, apart from modifying binding site residues.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Escherichia coli Proteins
/
Periplasmic Binding Proteins
/
Escherichia coli
/
Mutation
Language:
En
Journal:
J Mol Biol
Year:
2021
Document type:
Article
Affiliation country: