title: Properties of the indole ring in metal complexes. A comparison with the phenol ring.
abstract: Tryptophan (Trp), an essential amino acid, has an indole ring with a high electron density and is frequently seen at the proximal position of the metal site in metalloproteins. For example, the indole ring of Trp has been reported to interact weakly with Cu(I) in a Cu chaperone CusF. Another aromatic amino acid, tyrosine (Tyr), has a phenol ring, which is an important metal binding site in various metalloproteins. Although the structures of the aromatic rings are different, they both have a weakly acidic moiety and perform some similar roles in biological systems, such as radical formation and electron transfer. In this review, we focus on these and other properties of the indole and phenol rings in metal-containing systems.
authors: College of Science, Ibaraki University, Mito310-8512, Japan. Electronic address: yshima@mx.ibaraki.ac.jp.
authors: Yuichi
authors: Y
authors: Shimazaki
authors: Faculty of Chemistry, Materials and Bioengineering, Kansai University, Suita, Osaka564-8680, Japan.
authors: Tatsuo
authors: T
authors: Yajima
authors: Faculty of Chemistry, Materials and Bioengineering, Kansai University, Suita, Osaka564-8680, Japan; Department of Chemistry, School of Science, Nagoya University, Chikusa-ku, Nagoya464-8602, Japan. Electronic address: oyamauchi36bioin@wonder.ocn.ne.jp.
authors: Osamu
authors: O
authors: Yamauchi
mesh_terms: D001665:Binding Sites; D056831:Coordination Complexes / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry*; D008667:Metalloproteins / Q000737:chemistry; D008670:Metals / Q000737:chemistry*; D008956:Models, Chemical; D015394:Molecular Structure; D019800:Phenol / Q000737:chemistry*; D014364:Tryptophan / Q000737:chemistry; D014443:Tyrosine / Q000737:chemistry
chemical_list: D056831:Coordination Complexes; D007211:Indoles; D008667:Metalloproteins; D008670:Metals; D019800:Phenol; D014443:Tyrosine; C030374:indole; D014364:Tryptophan
keywords: Metal complexes; Radical formation; Tryptophan; Tyrosine; σ- and π-bondings