The crystal structure of red fluorescent protein TagRFP-T reveals the mechanism of its superior photostability

Journal Article · Fri Aug 19 04:00:00 EDT 2016 · Biochemical and Biophysical Research Communications

DOI:https://doi.org/10.1016/J.BBRC.2016.06.047· OSTI ID:22606159

Liu, Rui; Liang, Qing-Nan; Du, Shu-Qi; Hu, Xiao-Jian; Ding, Yu

The red fluorescent protein variant TagRFP-T has greatly improved photostability over its parent molecule, TagRFP, but the underlying mechanism leading to this improvement is to date unknown. The 1.95 Å resolution crystallographic structure of TagRFP-T showed that its chromophore exists as a mixture of cis and trans coplanar isomers in roughly equal proportions. Interestingly, both isomers are able to fluoresce, a property that has never been observed in any other fluorescent protein. We propose a “circular restoration model” for TagRFP-T to explain its superior photostability: There are four co-existing chromophore states (cis/trans protonated/ionized state) that can be driven by light to transform from one state into another. This model also explains how TagRPF-T essentially eliminates the temporary dark state (reversible photobleaching). - Highlights: • The 1.95 Å resolution crystal structure of TagRFP-T was determined. • The chromophore of TagRFP-T contains a mixture of cis and trans coplanar isomers. • A “circular restoration model” was proposed to explain the superior photostability. • The chromophore can reversibly convert between cis/trans protonated/ionized states. • The light-driven conversion reduce the dark state (reversible photobleaching).

• OSTI ID: 22606159
• Journal Information: Biochemical and Biophysical Research Communications, Journal Name: Biochemical and Biophysical Research Communications Journal Issue: 2 Vol. 477; ISSN 0006-291X; ISSN BBRCA9
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
BIOLOGICAL RECOVERY
CRYSTAL STRUCTURE
CRYSTALLOGRAPHY
EXCITED STATES
FLUORESCENCE
ISOMERS
PROTEINS