Designing brighter near-infrared fluorescent proteins: insights from structural and biochemical studies.Baloban, M., Shcherbakova, D.M., Pletnev, S., Pletnev, V.Z., Lagarias, J.C., Verkhusha, V.V.
(2017) Chem Sci 8: 4546-4557
- PubMed: 28936332
- DOI: 10.1039/c7sc00855d
- Primary Citation of Related Structures:
- PubMed Abstract:
Brighter near-infrared (NIR) fluorescent proteins (FPs) are required for multicolor microscopy and deep-tissue imaging. Here, we present structural and biochemical analyses of three monomeric, spectrally distinct phytochrome-based NIR FPs, termed miR ...
Brighter near-infrared (NIR) fluorescent proteins (FPs) are required for multicolor microscopy and deep-tissue imaging. Here, we present structural and biochemical analyses of three monomeric, spectrally distinct phytochrome-based NIR FPs, termed miRFPs. The miRFPs are closely related and differ by only a few amino acids, which define their molecular brightness, brightness in mammalian cells, and spectral properties. We have identified the residues responsible for the spectral red-shift, revealed a new chromophore bound simultaneously to two cysteine residues in the PAS and GAF domains in blue-shifted NIR FPs, and uncovered the importance of amino acid residues in the N-terminus of NIR FPs for their molecular and cellular brightness. The novel chromophore covalently links the N-terminus of NIR FPs with their C-terminal GAF domain, forming a topologically closed knot in the structure, and also contributes to the increased brightness. Based on our studies, we suggest a strategy to develop spectrally distinct NIR FPs with enhanced brightness.
Macromolecular Crystallography Laboratory , National Cancer Institute , Leidos Biomedical Research Inc. , Basic Research Program , Argonne , Illinois 60439 , USA.,Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry , Russian Academy of Sciences , Moscow 117997 , Russian Federation.,Department of Molecular and Cellular Biology , University of California in Davis , California 95616 , USA.,Department of Anatomy and Structural Biology and Gruss-Lipper Biophotonics Center , Albert Einstein College of Medicine , Bronx , New York 10461 , USA . Email: firstname.lastname@example.org.,Department of Biochemistry and Developmental Biology , Faculty of Medicine , University of Helsinki , Helsinki 00029 , Finland.