Deeply inverted electron-hole recombination in a luminescent antibody-stilbene complex.
The blue-emissive antibody EP2-19G2 that has been elicited against trans-stilbene has unprecedented ability to produce bright luminescence and has been used as a biosensor in various applications. We show that the prolonged luminescence is not stilbene fluorescence. Instead, the emissive species is a charge-transfer excited complex of an anionic stilbene and a cationic, parallel pi-stacked tryptophan. Upon charge recombination, this complex generates exceptionally bright blue light. Complex formation is enabled by a deeply penetrating ligand-binding pocket, which in turn results from a noncanonical interface between the two variable domains of the antibody.
Debler
Erik W
EW
Department of Molecular Biology, Scripps Research Institute, La Jolla, CA 92037, USA.
Kaufmann
Gunnar F
GF
Meijler
Michael M
MM
Heine
Andreas
A
Mee
Jenny M
JM
Pljevaljcic
Goran
G
Di Bilio
Angel J
AJ
Schultz
Peter G
PG
Millar
David P
DP
Janda
Kim D
KD
Wilson
Ian A
IA
Gray
Harry B
HB
Lerner
Richard A
RA
D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000235:genetics / Q000276:immunology; D000936:Antigen-Antibody Complex; D001666:Binding Sites, Antibody; D003460:Crystallization; D018360:Crystallography, X-Ray; D004583:Electrons; D005453:Fluorescence; D005454:Fluorescence Polarization; D006241:Haptens / Q000737:chemistry / Q000276:immunology; D057927:Hydrophobic and Hydrophilic Interactions; D007135:Immunoglobulin Variable Region / Q000737:chemistry* / Q000276:immunology; D008024:Ligands; D049449:Luminescence; D009154:Mutation; D010084:Oxidation-Reduction; D017434:Protein Structure, Tertiary; D013050:Spectrometry, Fluorescence; D013057:Spectrum Analysis; D013267:Stilbenes / Q000737:chemistry* / Q000276:immunology; D014364:Tryptophan / Q000737:chemistry
D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D006241:Haptens; D007135:Immunoglobulin Variable Region; D008024:Ligands; D013267:Stilbenes; D014364:Tryptophan