Immunohistochemical detection of S-nitrosylated proteins.

Accumulating evidence shows that S-nitrosothiols, formed by the addition of nitric oxide (NO) to a cysteine thiol, S-nitrosylation, are involved in basal cellular regulation. It has been proposed that SNO formation/removal may be disrupted in a variety of pathophysiological conditions. Two types of methodology are presently available to identify specific S-nitrosylated proteins: (1) derivatization and (2) post-purification chemical detection. Neither of these techniques allows for in situ visualization of SNOs. Recently, we demonstrated that an antibody generated to the SNO moiety could be used to detect SNO formation from each of three isoforms of NOS by immunohistochemistry. This chapter details the immunohistochemical methodology used to detect SNOs in situ, offering a potentially powerful alternative for detection of SNO within tissue sections.