Compositions and methods are provided for reversibly binding chitin
binding domain (CBD) to a chitin or equivalent substrate under non denaturing conditions.
CBD is modified preferably by a mutation to achieve this change in properties.
In one embodiment, an aromatic amino acid residue located in the binding cleft
of the CBD was altered resulting in reversible binding affinity for substrate in
select conditions. Creating a modified CBD with an altered binding affinity for
substrate provides new uses for CBD not previously possible with unmodified CBD
which binds irreversibly to chitin.
