Figure 2.

JNK2 is sulfenylated in response to FN-f and H₂O₂. A, human articular chondrocytes were treated for 60 min with either FN-f or increasing doses of H₂O₂. DCP-Bio1 (1 mm) was added in the last 3 min of treatment time before lysis. Cells were lysed, and DCP-Bio1–labeled proteins were captured using streptavidin affinity columns with an internal standard of prebiotinylated AhpC added for confirmation of experimental elution efficiency. Enriched samples were analyzed by immunoblotting using antibodies for total JNK2 (t-JNK2) and AhpC. A blot representative of three independent experiments is shown. B, BIAM labeling after thiol blocking and reduction of lysates from human articular chondrocytes treated with FN-f or a dose curve of H₂O₂ was performed as detailed under “Experimental procedures,” and lysates were analyzed as shown in A. A blot representative of three independent experiments is shown.