Structure and Function of the Engineered Multicopper Oxidase CueO from Escherichia coli-Deletion of the Methionine-Rich Helical Region Covering the Substrate-Binding Site
スポンサーリンク
概要
- 論文の詳細を見る
CueO is a multicopper oxidase (MCO) that is involved in the homeostasis of Cu in Escherichia coli and is the sole cuprous oxidase to have ever been found. Differing from other MCOs, the substrate-binding site of CueO is deeply buried under a methionine-rich helical region including α-helices 5, 6, and 7 that interfere with the access of organic substrates. We deleted the region Pro357-His406 and replaced it with a Gly-Gly linker. The crystal structures of a truncated mutant in the presence and in the absence of excess Cu(II) indicated that the scaffold of the CueO molecule and metal-binding sites were reserved in comparison with those of CueO. In addition, the high thermostability of the protein molecule and its spectroscopic and magnetic properties due to four Cu centers were also conserved after truncation. As for functions, the cuprous oxidase activity of the mutant was reduced to ca 10% that of recombinant CueO owing to the decrease in the affinity of the labile Cu site for Cu(I) ions, although activities for laccase substrates such as 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), p-phenylenediamine, and 2,6-dimethoxyphenol increased due to changes in the access of these organic substrates to the type I Cu site. The present engineering of CueO indicates that the methionine-rich α-helices function as a barrier to the access of bulky organic substrates, which provides CueO with specificity as a cuprous oxidase. © 2007 Elsevier Ltd. All rights reserved.
- 2007-10-12
論文 | ランダム
- ACTH independent macronodula adrena hyperplasia(AIMAHA)によるPre-Cushing症候群の1例
- P-126 既治療進行非小細胞肺癌に対するTS-1+biweekly CPT-11併用化学療法第I相試験(化学療法2,第49回日本肺癌学会総会号)
- 22.初回化学放射線療法の著効直後に,急速な腹腔内転移を来した肺腺癌の1例(第92回日本肺癌学会中部支部会,中部支部,支部活動)
- Klebsiella肺炎4例の画像的検討
- Taxotere/Adriamycin/Cyclophosphamide(TAC)療法が奏功した乳癌胸腔内転移の1例