TY - JOUR
T1 - Design of Highly Fluorinated Peptides for Cell-based 19F NMR
AU - Li, Jiaqian
AU - Kirberger, Steven E
AU - Wang, Yiao
AU - Cui, Huarui
AU - Wagner, Carston R.
AU - Pomerantz, William C.K.
N1 - Publisher Copyright:
© 2023 American Chemical Society.
PY - 2023/8/16
Y1 - 2023/8/16
N2 - The design of imaging agents with high fluorine content is essential for overcoming the challenges associated with signal detection limits in 19F MRI-based molecular imaging. In addition to perfluorocarbon and fluorinated polymers, fluorinated peptides offer an additional strategy for creating sequence-defined 19F magnetic resonance imaging (MRI) imaging agents with a high fluorine signal. Our previously reported unstructured trifluoroacetyllysine-based peptides possessed good physiochemical properties and could be imaged at high magnetic field strength. However, the low detection limit motivated further improvements in the fluorine content of the peptides as well as removal of nonspecific cellular interactions. This research characterizes several new highly fluorinated synthetic peptides composed of highly fluorinated amino acids. 19F NMR analysis of peptides TB-1 and TB-9 led to highly overlapping, intense fluorine resonances and acceptable aqueous solubility. Flow cytometry analysis and fluorescence microscopy further showed nonspecific binding could be removed in the case of TB-9. As a preliminary experiment toward developing molecular imaging agents, a fluorinated EGFR-targeting peptide (KKKFFKK-βA-YHWYGYTPENVI) and an EGFR-targeting protein complex E1-DD bioconjugated to TB-9 were prepared. Both bioconjugates maintained good 19F NMR performance in aqueous solution. While the E1-DD-based imaging agent will require further engineering, the success of cell-based 19F NMR of the EGFR-targeting peptide in A431 cells supports the potential use of fluorinated peptides for molecular imaging.
AB - The design of imaging agents with high fluorine content is essential for overcoming the challenges associated with signal detection limits in 19F MRI-based molecular imaging. In addition to perfluorocarbon and fluorinated polymers, fluorinated peptides offer an additional strategy for creating sequence-defined 19F magnetic resonance imaging (MRI) imaging agents with a high fluorine signal. Our previously reported unstructured trifluoroacetyllysine-based peptides possessed good physiochemical properties and could be imaged at high magnetic field strength. However, the low detection limit motivated further improvements in the fluorine content of the peptides as well as removal of nonspecific cellular interactions. This research characterizes several new highly fluorinated synthetic peptides composed of highly fluorinated amino acids. 19F NMR analysis of peptides TB-1 and TB-9 led to highly overlapping, intense fluorine resonances and acceptable aqueous solubility. Flow cytometry analysis and fluorescence microscopy further showed nonspecific binding could be removed in the case of TB-9. As a preliminary experiment toward developing molecular imaging agents, a fluorinated EGFR-targeting peptide (KKKFFKK-βA-YHWYGYTPENVI) and an EGFR-targeting protein complex E1-DD bioconjugated to TB-9 were prepared. Both bioconjugates maintained good 19F NMR performance in aqueous solution. While the E1-DD-based imaging agent will require further engineering, the success of cell-based 19F NMR of the EGFR-targeting peptide in A431 cells supports the potential use of fluorinated peptides for molecular imaging.
UR - http://www.scopus.com/inward/record.url?scp=85167818426&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85167818426&partnerID=8YFLogxK
U2 - 10.1021/acs.bioconjchem.3c00245
DO - 10.1021/acs.bioconjchem.3c00245
M3 - Article
C2 - 37523271
AN - SCOPUS:85167818426
SN - 1043-1802
VL - 34
SP - 1477
EP - 1485
JO - Bioconjugate Chemistry
JF - Bioconjugate Chemistry
IS - 8
ER -