The action of N‐acetylglucosaminyltransferase‐V is prevented by the bisecting GlcNAc residue at the catalytic step

FEBS Letters

Eguchi, Hironobu¹  Ikeda, Yoshitaka¹  Sasai, Ken¹  Taniguchi, Naoyuki¹  Tsuda, Takeo¹  Honke, Koichi¹ 

[1] Department of Biochemistry, Osaka University Medical School, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan

关键词: Bisecting N-acetylglucosamine;    β1;    6-Branched N-acetylglucosamine;    Kinetic analysis;    N-Acetylglucosaminyltransferase-V;    N-Glycan;    GlcNAc and Gn;    N-acetylglucosamine;    GnT;    N-acetylglucosaminyltransferase;    N-glycan;    asparagine-linked glycan;    Man;    mannose;    Glc;    glucose;    PA;    2-aminopyridine;    GnGn-bi-PA;    PA-labeled agalactobiantennary oligosaccharide;    HPLC;    high performance liquid chromatography;    ESI-MS;    electrospray ionization mass spectrometry;    Gn-bisected bi-PA;    PA-labeled agalactobiantennary sugar chain with bisecting GlcNAc;    Glc-bisected bi-PA;    PA-labeled agalactobiantennary sugar chain with bisecting Glc;   

DOI  :  10.1016/S0014-5793(02)02916-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Using a purified protein and bisected acceptor oligosaccharides, we demonstrate that N-acetylglucosaminyltransferase (GnT)-V transfers a N-acetylglucosamine residue via a β1,6-linkage to the bisected oligosaccharides. We also kinetically characterized the substrate specificity of GnT-V with respect to the bisected oligosaccharide. Although the K _m values for the bisected acceptors were comparable to that for a non-bisected acceptor, the V _max values for the bisected acceptors were much lower than that for the non-bisected acceptor. These findings suggest that the acceptor specificity of GnT-V is determined by the catalytic process rather than by its binding to the substrate. It was also found that the presence of the 2-N-acetyl group in the bisecting monosaccharide moiety plays a critical role in determining the catalytic efficiency of the enzyme.

【 授权许可】

Unknown