Chemoselective Methionine Bioconjugation: Site-Selective Fluorine-18 Labeling of Proteins and Peptides.
Bioconjug Chem
; 31(8): 1908-1916, 2020 08 19.
Article
in En
| MEDLINE
| ID: mdl-32687313
ABSTRACT
Chemoselective methionine bioconjugation with alkyne-bearing oxaziridine and alkyne-bearing iodonium salts was investigated as a new platform for site-selective radiolabeling of proteins and peptides with fluorine-18. Alkyne-bearing sulfimide conjugates, resulting from oxaziridine modification, underwent copper-assisted alkyne-azide cycloaddition (CuAAC) with an 18F-labeled PEGylated azide to afford 18F-labeled triazoles in excellent radiochemical yields. Diazoester sulfonium salt bioconjugates, formed from alkyne-bearing 2-diazoiodonium salts, gave low yields of 18F-labeled triazoles and were shown to be unstable to CuAAC conditions. Photolytic removal of the diazo group, however, afforded the trialkylsulfonium salt which smoothly underwent CuAAC with the 18F-labeled PEGylated azide to afford high radiochemical yields of the desired 18F-labeled click product. Overall, the results establish the viability of chemoselective methionine bioconjugation as a method for preparing site-selective 18F-labeled PET radioligands.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Peptides
/
Fluorine Radioisotopes
/
Proteins
/
Methionine
Language:
En
Journal:
Bioconjug Chem
Journal subject:
BIOQUIMICA
Year:
2020
Document type:
Article