Allosteric transition induced by Mg²⁺ ion in a transactivator monitored by SERS.
We demonstrate the utility of the surface-enhanced Raman spectroscopy (SERS) to monitor conformational transitions in protein upon ligand binding. The changes in protein's secondary and tertiary structures were monitored using amide and aliphatic/aromatic side chain vibrations. Changes in these bands are suggestive of the stabilization of the secondary and tertiary structure of transcription activator protein C in the presence of Mg(2+) ion, whereas the spectral fingerprint remained unaltered in the case of a mutant protein, defective in Mg(2+) binding. The importance of the acidic residues in Mg(2+) binding, which triggers an overall allosteric transition in the protein, is visualized in the molecular model. The present study thus opens up avenues toward the application of SERS as a potential tool for gaining structural insights into the changes occurring during conformational transitions in proteins.
Light Scattering Laboratory, Chemistry and Physics of Material Unit, Jawaharlal Nehru Center for Advanced Scientific Research , Jakkur, Bangalore 560064, India.
Partha P
PP
Kundu
Tuhin
T
Bhowmick
Ganduri
G
Swapna
G V
GV
Pavan Kumar
Valakunja
V
Nagaraja
Chandrabhas
C
Narayana
D000494:Allosteric Regulation; D001665:Binding Sites; D003102:Colloids / Q000737:chemistry; D007477:Ions / Q000737:chemistry; D008274:Magnesium / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D009154:Mutation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012834:Silver / Q000737:chemistry; D013059:Spectrum Analysis, Raman; D015534:Trans-Activators / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
D003102:Colloids; D007477:Ions; D015534:Trans-Activators; D012834:Silver; D008274:Magnesium