8-Anilinonaphthalene-1-sulfonic acid (ANS), also called 1-anilino-8-naphthalenesulfonate, is an organic compound containing both a

sulfonic acid In organic chemistry, sulfonic acid (or sulphonic acid) refers to a member of the class of organosulfur compounds with the general formula , where R is an organic alkyl or aryl group and the group a sulfonyl hydroxide. As a substituent, it is kn ...

and an amine group. This compound is used as a fluorescent molecular probe. For example, ANS can be used to study conformational changes induced by ligand binding in

proteins Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

, as ANS's fluorescent properties will change as it binds to hydrophobic regions on the protein surface. Comparison of the fluorescence in the presence and absence of a particular ligand can thus give information about how the binding of the ligand changes the surface of the protein. Its permeability to

mitochondrial A mitochondrion (; ) is an organelle found in the cells of most Eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is use ...

membranes makes it particularly useful.

References

Naphthalenesulfonic acids Fluorescent dyes Anilines {{organic-compound-stub