Wednesday, June 19, 2013

Fun fact: Popular sushi item contains the first vertebrate fluorescent protein

The Japanese freshwater eel has long been a staple at sushi bars. However, based on a report from Cell this eel may hold the key to advancing biological imaging. The report entitled: 'A Bilirubin-Inducible Fluorescent Protein from Eel Muscle' describes the cloning and characterization of UnaG; the first vertebrate fluorescent protein.

Anguilla japonica the Japanese freshwater eel

The authors show that UnaG belongs to the fatty-acid binding protein family whose fluorescence is induced by binding bilirubin rather than using a chromophore; the portion of a common fluorescent protein molecule that absorbs excitation light energy at a specific wavelength and produces colored light at a distinct emission wavelength. Bilirubin is a heme metabolite which has been used in hospital tests for liver function. As a result the authors also designed a human bilirubin detection assay that has potential clinical application as it is simpler, more sensitive and uses smaller sample volume.

Another interesting characteristic of UnaG is that it fluoresces in anaerobic environments. This may allow it to be used to analyze cells where oxygen levels are low such as the interior of tumors. The possible implications of this new ligand-induced fluorescent protein are numerous and we at BMG LABTECH are interested to see where this leads the field of fluorescent detection!