title: Low-temperature resonance-Raman spectra of Japanese-lacquer-tree (Rhus vernicifera) laccase, type-2-copper-depleted laccase and H2O2-treated type-2-copper-depleted laccase.
abstract: Resonance-Raman spectra of Japanese-lacquer-tree (Rhus vernicifera) laccase, type-2-copper-depleted laccase and the latter form treated with H2O2 were measured in liquid and frozen solution, on excitation into the 600 nm absorption band. Significant changes in intensity and/or frequency of the bands lying in the 370-430 cm-1 region were observed on freezing, indicating local structural rearrangements taking place at the blue copper site. These findings corroborate previous suggestions based on e.p.r. measurements and redox data [Morpurgo, Calabrese, Desideri & Rotilio (1981) Biochem. J. 193, 639-642]. They show the strong dependence of the physical properties of blue copper centres on local symmetry. Some conclusions on the origin of the Raman bands are also drawn.
mesh_terms: D003080:Cold Temperature; D003300:Copper; D006861:Hydrogen Peroxide / Q000494:pharmacology; D042845:Laccase; D010088:Oxidoreductases; D010947:Plants, Toxic; D013059:Spectrum Analysis, Raman; D012251:Toxicodendron / Q000201:enzymology*; D014197:Trees
chemical_list: D003300:Copper; D006861:Hydrogen Peroxide; D010088:Oxidoreductases; D042845:Laccase