Coordination environment for the type 3 copper center of tree laccase and CuB of cytochrome c oxidase as determined by electron nuclear double resonance.

Journal Article (Journal Article)

A new rhombic EPR signal was recently discovered in the partially reduced type 2 copper-depleted Rhus vernicifera laccase (Reinhammar, B. (1983) J. Inorg. Biochem., in press). The signal originates from one of the type 3 Cu(II) ions that becomes EPR-detectable as a result of the selective reduction of the other copper ion in the exchange-coupled Cu(II)-Cu(II) pair. The 14N and 1H and 63,65Cu electron nuclear double resonance (ENDOR) of this uncoupled Cu(II) now have been collected and represent the first ENDOR measurements of a type 3 copper site. The data indicate that the copper is coordinated by at least three nitrogenous ligands, at least one of which is an imidazole. H/D exchange suggests a nearby H2O or OH-, perhaps as a fourth ligand. A similar EPR signal is seen for CuB of reduced cytochrome c oxidase under turnover conditions. The 14N ENDOR, and, therefore, the structure, of this site corresponds extremely closely to that of the laccase type 3 (Cu(II).

Full Text

Duke Authors

Cited Authors

  • Cline, J; Reinhammar, B; Jensen, P; Venters, R; Hoffman, BM

Published Date

  • April 25, 1983

Published In

Volume / Issue

  • 258 / 8

Start / End Page

  • 5124 - 5128

PubMed ID

  • 6300117

International Standard Serial Number (ISSN)

  • 0021-9258

Language

  • eng

Conference Location

  • United States