Figure 3.

S-Nitroso-pannexin1 in diabetic corneal synaptosomes. Biotin switch assay revealed diminution of S-nitroso-pannexin1 in synaptosomes obtained from diabetic nerve terminals. Normal control varicosities showed significantly increased S-nitrosylation signals, which were also enhanced by external stimulation with the nitric oxide donors GSNO and DEA NONOate. Synaptosomal treatment with the reducing agent DTT (1 mM) immediately after GSNO or DEA NONOate treatment to reduce S-nitrosothiols prevented the biotinylation reaction. In addition, S-nitrosylation of Panx1 was not seen when ascorbic acid was not added to prevent the availability of free S-nitrosylated cysteines for subsequent biotinylation. DEA NONOate = diethylamine NONOate, DTT = dithiothreitol, GSNO = S-nitrosoglutathione.