The electronic spectrum of Co(II) in the type 1 site of rhus vernicifera laccase

Abstract

The absorption bands of Co(II) bound in the type 1 site of Rhus vernicifera laccase have been resolved by difference spectroscopy in conjunction with a laccase sample containing Hg(II) in the type 1 site. At pH 8 dd band maxima occur at 540 and 595 nm, and the charge transfer maximum occurs at c. 303 nm. The results suggest that the type 1 site in laccase may have a distinctive axial ligand field. In particular, the spread in the visible bands of Co(II) is relatively narrow by comparion with other derivatives, and the charge transfer absorption is hypsochromically shifted as well.