Fig. 6.

BB-Cl-amidine impairs STING oligomerization via the modification of Cys¹⁴⁸. (A) Representative mass spectrometry spectra of STING modified by BB-Cl-amidine identified in tryptic digests from recombinant STING (10 μg) incubated with BB-Cl-amidine (10 μM) for 1 h at 37 °C. (B) Immunoblot analysis of STING in native and reduced fractions from lysates of HEK293T cells expressing WT murine STING or a murine STING-C147S mutant and treated with diABZI-4 for 15 min. (C) Immunoblot analysis of STING in native and reduced fractions of lysates from BMDMs pretreated with the indicated concentrations of BB-Cl-amidine followed by treatment with diABZI-4. (D) Immunoblot analysis of STING in native and reduced fractions of lysates from WT and Padi4^−/− BMDMs treated with 500 nM diABZI for the indicated times.