書誌事項
- タイトル別名
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- Properties of Branching Enzyme from Hyperthermophilic Bacterium, Aquifex aeolicus, and Its Potential for Production of Highly-branched Cyclic Dextrin.
抄録
By sequencing the whole genome of the hyperthermophilic bacterium, Aquifex aeolicus, a gene (Aq722) encoding a protein with high similarity to the branching enzyme (BE, EC 2.4.1.18) has been found. Based on the putative amino acid sequence, a polynucleotide encoding the BE gene was chemically synthesized and the gene was expressed in Escherichia coli. More than 95% of the recombinant enzyme was present within the cells as insoluble but catalytically active aggregates. Heat treatment of the aggregate suspension at 70°C resulted in about 30% solubilization of the BE activity. Enzymatic properties of both soluble and insoluble forms of the BE were analyzed. Both forms exhibited maximum activities at 75°C and pH 7.5-8.0, and were stable at temperatures up to 85°C. The insolubleform BE was less stable than the soluble form in neutral and acidic pH regions; after 30-min incubation at 70°C and pH 7.0, 90 and 50% activities of soluble andinsoluble forms remained, respectively. When amylopectin was used as a substrate, the A. aeolicus BE cyclized the B-chains, which connect the cluster structures of amylopectin. The product (highly-branched cyclic dextrin), with weight-average degree of polymerization (DPw) 1200, has a ring structure with DPw 50 and noncyclic chains with an average unit chain length of 16 connected to the ring.
収録刊行物
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- Journal of Applied Glycoscience
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Journal of Applied Glycoscience 50 (1), 15-20, 2003
日本応用糖質科学会
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詳細情報 詳細情報について
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- CRID
- 1390001206292097536
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- NII論文ID
- 130002000829
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- COI
- 1:CAS:528:DC%2BD3sXhs1eksLo%3D
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- ISSN
- 18807291
- 13447882
- http://id.crossref.org/issn/13447882
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- 本文言語コード
- en
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- データソース種別
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- JaLC
- Crossref
- CiNii Articles
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- 抄録ライセンスフラグ
- 使用不可