Binding to a quaternary ammonium group, including glycine betaine, choline, carnitine and proline. A quaternary ammonium group is any compound that can be regarded as derived from ammonium hydroxide or an ammonium salt by replacement of all four hydrogen atoms of the NH4+ ion by organic groups. [ GOC:ai ]
Synonyms: quaternary amine binding
This is just here as a test because I lose it