Spectral and structural comparison between bright and dim green fluorescent proteins in Amphioxus
Erin K Bomati1, Joy E Haley2, Joseph P Noel3
1Marine Biology Research Division, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92037 USA.
Scientific Reports
|June 28, 2014
Summary
Cephalochordate Amphioxus reveals key molecular features driving fluorescent protein (FP) brightness. Understanding these structure-function relationships enhances FP engineering for improved fluorescence intensity.
Area of Science:
- Biochemistry
- Structural Biology
- Molecular Biology
Background:
- Cephalochordate Amphioxus naturally co-expresses fluorescent proteins (FPs) with varying brightness.
- This provides a unique model to identify molecular determinants of FP fluorescence intensity.
Purpose of the Study:
- To characterize the spectral and structural properties of a highly bright green FP (bfloGFPa1) and a dim counterpart (bfloGFPc1).
- To elucidate the structure-function relationship governing FP brightness.
Main Methods:
- Comparative spectral and structural analysis of two co-expressed FPs from Amphioxus.
- Investigation of chromophore environment and its impact on quantum efficiency and brightness.
Main Results:
- Bright bfloGFPa1 exhibits 100% quantum efficiency, while dim bfloGFPc1 has 0.1% quantum efficiency.
- Specific amino acid interactions (Tyr159, Trp157, Pro55) in bfloGFPa1 lead to chromophore repositioning, increased stability, and high brightness.
Conclusions:
- A direct link between chromophore structural environment and FP brightness is established.
- Insights gained can guide future engineering of fluorescent proteins with enhanced photonic properties.
