Division of Molecular Cell Biology, Department of Biomolecular Sciences, Saga University Faculty of Medicine, 5-1-1 Nabeshima, Saga 849-8501, Japan.
Division of Molecular Cell Biology, Department of Biomolecular Sciences, Saga University Faculty of Medicine, 5-1-1 Nabeshima, Saga 849-8501, Japan.
Biochem Biophys Res Commun. 2014 Jul 25;450(2):953-60. doi: 10.1016/j.bbrc.2014.06.087. Epub 2014 Jun 25.
Although core α1,6-fucosylation is commonly observed in N-glycans of both vertebrates and invertebrates, the responsible enzyme, α1,6-fucosyltransferase, has been much less characterized in invertebrates compared to vertebrates. To investigate the functions of α1,6-fucosyltransferase in insects, we cloned the cDNA for the α1,6-fucosyltransferase from Bombyx mori (Bmα1,6FucT) and characterized the recombinant enzyme prepared using insect cell lines. The coding region of Bmα1,6FucT consists of 1737bp that code for 578 amino acids of the deduced amino acid sequence, showing significant similarity to other α1,6-fucosyltransferases. Enzyme activity assays demonstrated that Bmα1,6FucT is enzymatically active in spite of being less active compared to the human enzyme. The findings also indicate that Bmα1,6FucT, unlike human enzyme, is N-glycosylated and forms a disulfide-bonded homodimer. These findings contribute to a better understanding of roles of α1,6-fucosylation in invertebrates and also to the development of the more efficient engineering of N-glycosylation of recombinant glycoproteins in insect cells.
尽管核心 α1,6-岩藻糖基化在脊椎动物和无脊椎动物的 N-聚糖中普遍存在，但与脊椎动物相比，无脊椎动物中负责该反应的 α1,6-岩藻糖基转移酶的特性要少得多。为了研究 α1,6-岩藻糖基转移酶在昆虫中的功能，我们从家蚕（Bombyx mori）中克隆了 α1,6-岩藻糖基转移酶的 cDNA，并利用昆虫细胞系对重组酶进行了表征。Bmα1,6FucT 的编码区由 1737bp 组成，编码 578 个氨基酸的推导氨基酸序列，与其他 α1,6-岩藻糖基转移酶具有显著的相似性。酶活性测定表明，尽管与人类酶相比活性较低，但 Bmα1,6FucT 具有酶活性。研究结果还表明，Bmα1,6FucT 与人类酶不同，它是 N-糖基化的，并形成二硫键连接的同源二聚体。这些发现有助于更好地理解 α1,6-岩藻糖基化在无脊椎动物中的作用，也有助于更有效地工程改造昆虫细胞中重组糖蛋白的 N-糖基化。
