AN IMMUNOASSAY FOR THE DETECTION AND QUANTITATIVE-DETERMINATION OF MYCOTHIOL

Mycothiol (MSH) is a glycosylated derivative of N-acetylcysteine that may have antioxidant functions in mycobacteria and other actinomycetes . To develop a highly specific assay for MSH, we capitalized on the se lective binding of thiols to a maleimide residue linked to bovine seru m albumin and employed affinity-purified polyclonal antibody and an en zyme-linked secondary antibody for detection. The assay was shown to b e specific and to detect MSH at levels as low as 0.1 pmol when conduct ed in the form of a microtiter plate-based ELISA. A similar, nitrocell ulose membrane-based immunoassay was shown to be useful for qualitativ e detection of MSH-producing bacterial colonies. (C) 1998 Elsevier Sci ence B.V. All rights reserved.