Does anyone know the relationship between the number of
histidine residues and the binding affinity to Zn++?
We are working with an enzyme with 3 identical subunits.
We would like to make hybrid enzymes containing 1, 2, and
3 mutant subunits, purify them, and analyze the kinetics.
The present scheme is to add 3 His residues on the end of
the wild type subunit by genetic engineering, expressing
this in the presence of the gene coding for the mutant
subunit, and purifing the hybrid molecules by Zn chelate
affinity chromatography. For this to work, all three of
the hybrid molecules must differ significantly in their
ability to bind to Zn++.
Department of Biological Chemistry
The Chicago Medical School
North Chicago IL