Publications

• Copper-O2 reactivity of tyrosinase models towards external monophenolic substrates: molecular mechanism and comparison with the enzyme.

  Rolff M., Schottenheim J., Decker H., Tuczek F.

  The critical review describes the known dicopper systems mediating the aromatic hydroxylation of monophenolic substrates. Such systems are of interest as structural and functional models of the type 3 copper enzyme tyrosinase, which catalyzes the ortho-hydroxylation of tyrosine to DOPA and the sub ... >> More

  The critical review describes the known dicopper systems mediating the aromatic hydroxylation of monophenolic substrates. Such systems are of interest as structural and functional models of the type 3 copper enzyme tyrosinase, which catalyzes the ortho-hydroxylation of tyrosine to DOPA and the subsequent two-electron oxidation to dopaquinone. Small-molecule systems involving μ-η²:η² peroxo, bis-μ-oxo and trans-μ-1,2 peroxo dicopper cores are considered separately. These tyrosinase models are contrasted to copper-dioxygen systems inducing radical reactions, and the different mechanistic pathways are discussed. In addition to considering the stoichiometric conversion of phenolic substrates, the available catalytic systems are described. The second part of the review deals with tyrosinase. After an introduction on the occurrence and function of tyrosinases, several aspects of the chemical reactivity of this class of enzymes are described. The analogies between the small-molecule and the enzymatic system are considered, and the implications for the reaction pathway of tyrosinase are discussed (140 references). << Less

  Chem Soc Rev 40:4077-4098(2011) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• Purification, characterization, and molecular cloning of tyrosinase from Pholiota nameko.

  Kawamura-Konishi Y., Tsuji M., Hatana S., Asanuma M., Kakuta D., Kawano T., Mukouyama E.B., Goto H., Suzuki H.

  Tyrosinase (monophenol, 3,4-dihydroxy L-phenylalanine (L-DOPA):oxygen oxidoreductase, EC 1.14.18.1) was isolated from fruit bodies of Pholiota nameko and purified to homogeneity. The purified enzyme was a monomer with a molecular weight of 42,000 and contained 1.9 copper atoms per molecule. The N- ... >> More

  Tyrosinase (monophenol, 3,4-dihydroxy L-phenylalanine (L-DOPA):oxygen oxidoreductase, EC 1.14.18.1) was isolated from fruit bodies of Pholiota nameko and purified to homogeneity. The purified enzyme was a monomer with a molecular weight of 42,000 and contained 1.9 copper atoms per molecule. The N-terminal of the purified enzyme could not be detected by Edman degradation, probably due to blocking, while the C-terminal sequence of the enzyme was determined to be -Ala-Ser-Val-Phe-OH. The amino acid sequence deduced by cDNA cloning was made up of 625 amino acid residues and contained two putative copper-binding sites highly conserved in tyrosinases from various organisms. The C-terminal sequence of the purified enzyme did not correspond to that of the deduced sequence, but agreed with Ala384-Ser385-Val386-Phe387 in sequence. When the encoded protein was truncated at Phe387, the molecular weight of the residual protein was calculated to be approximately 42,000. These results suggest that P. nameko tyrosinase is expressed as a proenzyme followed by specific cleavage to produce a mature enzyme. << Less

  Biosci. Biotechnol. Biochem. 71:1752-1760(2007) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• Assay for tyrosine hydroxylation activity of tyrosinase from betalain-forming plants and cell cultures.

  Steiner U., Schliemann W., Strack D.

  In our studies on tyrosinase-catalyzed tyrosine hydroxylation, possibly involved in betalain biosynthesis, we have evaluated different assays for the detection and quantification of the enzymatic product Dopa with respect to sensitivity, simplicity, and suitability for automatization. A tyrosinase ... >> More

  In our studies on tyrosinase-catalyzed tyrosine hydroxylation, possibly involved in betalain biosynthesis, we have evaluated different assays for the detection and quantification of the enzymatic product Dopa with respect to sensitivity, simplicity, and suitability for automatization. A tyrosinase assay including reversed-phase high-performance liquid chromatography with isocratic elution and fluorescence detection has been developed (native fluorescence of Dopa; excitation at 281 nm, emission at 314 nm). This improved assay was sensitive (detection limit: 2 pmol Dopa) and showed a wide linear range of Dopa detection (10 pmol-20 nmol Dopa). The method proved to be suitable for high-performance liquid chromatography with an autosampler and has been applied for measuring tyrosinase activity of cell cultures and different tissues of Portulaca grandiflora. << Less

  Anal Biochem 238:72-75(1996) [PubMed] [EuropePMC]

• Tyrosinase: a comprehensive review of its mechanism.

  Sanchez-Ferrer A., Rodriguez-Lopez J.N., Garcia-Canovas F., Garcia-Carmona F.

  Biochim Biophys Acta 1247:1-11(1995) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.