Using surface enhanced Raman scattering to analyze the interactions of protein receptors with bacterial quorum sensing modulators.
Many members of the LuxR family of quorum sensing (QS) transcriptional activators, including LasR of Pseudomonas aeruginosa, are believed to require appropriate acyl-homoserine lactone (acyl-HSL) ligands to fold into an active conformation. The failure to purify ligand-free LuxR homologues in nonaggregated form at the high concentrations required for their structural characterization has limited the understanding of the mechanisms by which QS receptors are activated. Surface-enhanced Raman scattering (SERS) is a vibrational spectroscopy technique that can be applied to study proteins at extremely low concentrations in their active state. The high sensitivity of SERS has allowed us to detect molecular interactions between the ligand-binding domain of LasR (LasRLBD) as a soluble apoprotein and modulators of P. aeruginosa QS. We found that QS activators and inhibitors produce differential SERS fingerprints in LasRLBD, and in combination with molecular docking analysis provide insight into the relevant interaction mechanism. This study reveals signal-specific structural changes in LasR upon ligand binding, thereby confirming the applicability of SERS to analyze ligand-induced conformational changes in proteins.
†Departamento de Química Física, Universidade de Vigo, 36301 Vigo, Spain.
Celina
C
Costas
†Departamento de Química Física, Universidade de Vigo, 36301 Vigo, Spain.
Vanesa
V
López-Puente
†Departamento de Química Física, Universidade de Vigo, 36301 Vigo, Spain.
Gustavo
G
Bodelón
‡Centro Singular de Investigación en Química Biológica y Materiales Moleculares (CIQUS), Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
Concepción
C
González-Bello
†Departamento de Química Física, Universidade de Vigo, 36301 Vigo, Spain.
Jorge
J
Pérez-Juste
†Departamento de Química Física, Universidade de Vigo, 36301 Vigo, Spain.
Isabel
I
Pastoriza-Santos
†Departamento de Química Física, Universidade de Vigo, 36301 Vigo, Spain.|§Bionanoplasmonics Laboratory, CIC biomaGUNE, Paseo de Miramón 182, 20009 Donostia-San Sebastian, Spain.|∥Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain.
Luis M
LM
Liz-Marzán
D001059:Apoproteins / Q000737:chemistry / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D006046:Gold / Q000737:chemistry; D008024:Ligands; D062105:Molecular Docking Simulation; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011550:Pseudomonas aeruginosa / Q000166:cytology*; D053038:Quorum Sensing / Q000187:drug effects; D013059:Spectrum Analysis, Raman; D013499:Surface Properties; D015534:Trans-Activators / Q000737:chemistry / Q000378:metabolism*
D001059:Apoproteins; D001426:Bacterial Proteins; C080365:LasR protein, Pseudomonas aeruginosa; D008024:Ligands; D015534:Trans-Activators; D006046:Gold
Pseudomonas aeruginosa; SERS; nanoplasmonics; protein receptors; quorum sensing