Ligand-induced conformational changes in protein molecules detected by sum-frequency generation.

ABSTRACT: We present the first demonstration of ligand-induced conformational changes in a biological molecule, a protein, by sum-frequency generation (SFG). Constructs of KRas^G12D protein were prepared by selectively deuterating residues of a single amino acid type using isotope-labeled amino acids and cell-free protein synthesis. By attaching labeled protein to a supported bilayer membrane via a His-tag to Ni-NTA-bearing lipids, we ensured that single layers of ordered molecules were formed while preserving the protein's native structure. Exceptionally large SFG amide I signals were produced in both labeled and unlabeled proteins, demonstrating a high degree of orientational order upon attachment to the bilayer. Deuterated protein also produced SFG signals in the CD_x spectral

SUBMITTER: Salafsky J 

PROVIDER: S-EPMC11560303 | biostudies-literature | 2024 Nov

REPOSITORIES: biostudies-literature