Fluorescent proteins, including the famous and commonly used green fluorescent protein (GFP), require an external light beam to strike the molecule for it to fluoresce. In the past, scientists have tried using luminescent proteins that are activated by other means, but their light was too dim and made them hard to see. Now Japanese researchers have developed so called “nano-lanterns,” luminescent proteins that light up in response to chemical changes rather than light, that are bright and produce different colored spectrum of light. This capability may be a huge benefit for biomedical researchers, allowing them to track all sorts of complicated mechanisms within the human body.
The research team from RIKEN Quantitative Biology Center and Osaka University used the sea pansy that produces the Renilla luciferase enzyme (named after Lucifer, the bearer of light) that reacts with and activates coelenterazine, a light emitting molecule. Under natural circumstances, this process results in a dim blue light that’s not very useful for researchers, but the researchers used a genetically altered form of the enzyme to couple it with three different colored fluorescent proteins. This resulted in thee luminescent compounds that can be used individually or together to follow different biochemical processes.
Conveniently, the light emitted by the new compounds is bright enough to be detected by a smartphone camera, which means that researchers can use them in situations where powerful microscopes are impractical or impossible.