Open AccessAnion Complexes of Cu(II) and Co(II) Bovine Carbonic Anhydrase as Models for the Copper Site of Blue Copper Proteins
Author(s) -
MORPURGO Laura,
FINAZZI AGRÓ Alessandro,
ROTILIO Guiseppe,
MONDOVÍ Bruno
Publication year - 1976
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1976.tb10322.x
Subject(s) - carbonic anhydrase , chemistry , copper , copper protein , carbonic anhydrase ii , inorganic chemistry , enzyme , sulfur , active site , acceptor , biochemistry , organic chemistry , physics , condensed matter physics
1 The presence of two intense transitions in the optical absorption spectrum of the sulfide and 2‐mercaptoethanol complexes of Cu(II) and Co(II)‐substituted bovine carbonic anhydrase suggests that charge‐transfer interactions between sulfur and an acceptor group of the protein play an important role in the stabilization of these complexes. 2 The spectra of Co(II) bovine carbonic anhydrase sulfides are very similar to the spectrum of Co(II) stellacyanin whilst the spectra of the corresponding Cu(II) enzymes are considerably different. A possible explanation is that Cu(II) is pentacoordinate in native stellacyanin unlike Cu(II) bovine carbonic anhydrase sulfides and Co(II) enzymes. Tetrahedral Co(II) stellacyanin is proposed as a model of the reduced copper site.