Article
Extended Data Fig. 9 | Upscaling of the protein modif ication with pySOOF
and^19 F NMR analysis. The scalability of protein modification reaction with
pySOOF was studied and high conversion efficiencies were observed for
pySOOF-Lys, LysAc, Lys(Me) 3 , Met, Glu and DfeGly using 4–6 mg of Dha-tagged
histone. After the photochemical reaction, the crude mixture was vortexed
with either EDTA or DTT, followed by buffer exchange to deuterated buffer
(NH 4 OAc, 250 mM, pH 7 in D 2 O with TFA as internal standard) using desalting
columns. After purification, excellent yields were determined by checking
the protein concentration by absorbance at 280 nm on a micro-volume
spectrophotometer. Spectra were recorded on a Bruker NMR system (AV600)
and all PTMs showed characteristic peaks with unique chemical shifts.