Structural and Functional Characterization of a Biliverdin-Binding Near-Infrared Fluorescent Protein From the Serpin Superfamily. Issue 2 (30th January 2022)

• Record Type: Journal Article
• Authors: Manoilov, Kyrylo Yu.; Ghosh, Agnidipta; Almo, Steven C.; Verkhusha, Vladislav V.
• Is Part Of: Journal of molecular biology. Volume 434:Issue 2(2022)
• Publication Date: 2022-01-30
• Subjects: biliprotein -- phytochrome -- tetrapyrrole -- fluorescent protein -- iRFP; α1-AT α1-antitrypsin -- BBS biliverdin-binding serpin -- BpBBS biliverdin-binding serpin of Boana punctata treefrog -- BV biliverdin -- NIR near-infrared -- FP fluorescent protein -- GuHCL guanidine hydrochloride; Molecular biology -- Periodicals; Biology -- Periodicals; Biochemistry -- Periodicals; Bacteriology -- Periodicals; Molecular Biology -- Periodicals; Biochemistry -- Periodicals; Biologie moléculaire -- Périodiques; Biologie -- Périodiques; Biochimie -- Périodiques; Moleculaire biologie; Biochemistry; Biology; Molecular biology; Periodicals; 572.805
• DOI: 10.1016/j.jmb.2021.167359
• Languages: English
• ISSNs: 0022-2836

Abstract

Graphical abstract: Abstract: Biliverdin-binding serpins (BBSs) are proteins that are responsible for coloration in amphibians and fluoresce in the near-infrared (NIR) spectral region. Here we produced the first functional recombinant BBS of the polka-dot treefrog Boana punctata ( Bp BBS), assembled with its biliverdin (BV) chromophore, and report its biochemical and photochemical characterization. We determined the crystal structure of Bp BBS at 2.05 Å resolution, which demonstrated its structural homology to the mammalian protease inhibitor alpha-1-antitrypsin. BV interaction with Bp BBS was studied and it was found that the N-terminal polypeptide (residues 19–50) plays a critical role in the BV binding. By comparing Bp BBS with the available NIR fluorescent proteins and expressing it in mammalian cells, we demonstrated its potential as a NIR imaging probe. These results provide insight into the non-inhibitory function of serpins, provide a basis for improving their performance in mammalian cells, and suggest possible paths for the development of BBS-based fluorescent probes.