By a News Reporter-Staff News Editor at Life Science Weekly -- Current study results on Sulfur Amino Acids have been published. According to news originating from Osaka, Japan, by NewsRx correspondents, research stated, "Tyrosinase, a dinuclear copper monooxygenase/oxidase, plays a crucial role in the melanin pigment biosynthesis. The structure and functions of tyrosinase have so far been studied extensively, but the post-translational maturation process from the pro-form to the active form has been less explored."
Our news journalists obtained a quote from the research from Osaka University, "In this study, we provide the crystal structures of Aspergillus oryzae full-length pro-tyrosinase in the holo-and the apo-forms at 1.39 and 2.05 ? resolution, respectively, revealing that Phe(513) on the C-terminal domain is accommodated in the substrate-binding site as a substrate analog to protect the dicopper active site from substrate access (proteolytic cleavage of the C-terminal domain or deformation of the C-terminal domain by acid treatment transforms the pro-tyrosinase to the active enzyme (Fujieda, N., Murata, M., Yabuta, S., Ikeda, T., Shimokawa, C., Nakamura, Y., Hata, Y., and Itoh, S. (2012) ChemBioChem. 13, 193-201 and Fujieda, N., Murata, M., Yabuta, S., Ikeda, T., Shimokawa, C., Nakamura, Y., Hata, Yl, and Itoh, S. (2013) J. Biol. Inorg. Chem. 18, 19-26). Detailed crystallographic analysis and structure-based mutational studies have shown that the copper incorporation into the active site is governed by three cysteines as follows: Cys(92), which is covalently bound to His(94) via an unusual thioether linkage in the holo-form, and Cys(522) and Cys(525) of the CXXC motif located on the C-terminal domain."
According to the news editors, the research concluded: "Molecular mechanisms of the maturation processes of fungal tyrosinase involving the accommodation of the dinuclear copper unit, the post-translational His-Cys thioether cross-linkage formation, and the proteolytic C-terminal cleavage to produce the active tyrosinase have been discussed on the basis of the detailed structural information."
For more information on this research see: Crystal structures of copper-depleted and copper-bound fungal pro-tyrosinase: insights into endogenous cysteine-dependent copper incorporation. Journal of Biological Chemistry, 2013;288(30):22128-40. (American Society for Biochemistry and Molecular Biology - www.asbmb.org; Journal of Biological Chemistry - www.jbc.org/)
The news correspondents report that additional information may be obtained from N. Fujieda, Dept. of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan. Additional authors for this research include S. Yabuta, T. Ikeda, T. Oyama, N. Muraki, G. Kurisu and S. Itoh (see also Sulfur Amino Acids).
Keywords for this news article include: Asia, Osaka, Japan, Cysteine, Sulfur Amino Acids, Neutral Amino Acids, Sulfhydryl Compounds.
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