Bright Green Biofluorescence in Sharks Derives from Bromo-Kynurenine Metabolism
Hyun Bong Park,
Yick Chong Lam,
Jean P. Gaffney,
James C. Weaver,
Sara Rose Krivoshik,
Randy Hamchand,
Vincent Pieribone,
David F. Gruber,
Jason M. Crawford
Affiliations
Hyun Bong Park
Department of Chemistry, Yale University, New Haven, CT 06520, USA; Chemical Biology Institute, Yale University, West Haven, CT 06516, USA
Yick Chong Lam
Department of Chemistry, Yale University, New Haven, CT 06520, USA; Chemical Biology Institute, Yale University, West Haven, CT 06516, USA
Jean P. Gaffney
Department of Natural Sciences, City University of New York Baruch College, New York, NY 10010, USA; The Graduate Center Program in Biology, City University of New York Baruch College, New York, NY 10016, USA
James C. Weaver
Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA 02138, USA
Sara Rose Krivoshik
Department of Natural Sciences, City University of New York Baruch College, New York, NY 10010, USA; The Graduate Center Program in Biology, City University of New York Baruch College, New York, NY 10016, USA
Randy Hamchand
Department of Chemistry, Yale University, New Haven, CT 06520, USA; Chemical Biology Institute, Yale University, West Haven, CT 06516, USA
Vincent Pieribone
The John B. Pierce Laboratory, Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT 06519, USA
David F. Gruber
Department of Natural Sciences, City University of New York Baruch College, New York, NY 10010, USA; The Graduate Center Program in Biology, City University of New York Baruch College, New York, NY 10016, USA; Corresponding author
Jason M. Crawford
Department of Chemistry, Yale University, New Haven, CT 06520, USA; Chemical Biology Institute, Yale University, West Haven, CT 06516, USA; Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT 06536, USA; Corresponding author
Summary: Although in recent years there has been an increased awareness of the widespread nature of biofluorescence in the marine environment, the diversity of the molecules responsible for this luminescent phenotype has been mostly limited to green fluorescent proteins (GFPs), GFP-like proteins, and fluorescent fatty acid-binding proteins (FABPs). In the present study, we describe a previously undescribed group of brominated tryptophan-kynurenine small molecule metabolites responsible for the green biofluorescence in two species of sharks and provide their structural, antimicrobial, and spectral characterization. Multi-scale fluorescence microscopy studies guided the discovery of metabolites that were differentially produced in fluorescent versus non-fluorescent skin, as well as the species-specific structural details of their unusual light-guiding denticles. Overall, this study provides the detailed description of a family of small molecules responsible for marine biofluorescence and opens new questions related to their roles in central nervous system signaling, resilience to microbial infections, and photoprotection. : Chemistry; Natural Product Chemistry; Natural Product Discovery Subject Areas: Chemistry, Natural Product Chemistry, Natural Product Discovery
