Oxygen treatment of horse liver alcohol dehydrogenase EE isoenzyme substituted with Cu(II) at the catalytic site leads to bleaching with concomitant reduction to Cu(I) of-90% of total Cu(II). The Cu(II) of the remaining 'minor species' cannot be reduced nor does it interact with exogenous ligands, e.g. 2-mercaploethanol, imidazole, purazole, or the azide ions. The EPR spectrum is axial with a super-hyperfine splitting of 15.6G indicating binding of one nitrogen atom to Cu(II). These data as well as the energies and intensities of the absorption and CD spectra suggest the Cu(II) ion of the minor species to be located in the catalytic site of HLADH in a position and geometry different from that of the major species. © 1992.
Formicka, G., Zeppezauer, M., Fey, F., & Hüttermann, J. (1992). Copper(II)-substituted horse liver alcohol dehydrogenase: Structure of the minor species. FEBS Letters, 309(1), 92–96. https://doi.org/10.1016/0014-5793(92)80747-5