A novel gene defining a novel human UDP-GlcNAc: Gal/Gl cNAc&bgr; 1-3GalNAc a&bgr;1, 6GlcNAc-transferase, termed C2/4GnT, with unique enzymatic properties is disclosed. The enzymatic activity of C2/4GnT is shown to be distinct from that of previously identified enzymes of this gene family. The invention discloses isolated DNA molecules and DNA constructs encoding C2/4GnT and derivatives thereof by way of amino acid deletion, substitution or insertion exhibiting C2/4GnT activity, as well as cloning and expression vectors including such DNA, cells transfected with the vectors, and recombinant methods for providing C2/4GnT. The enzyme C2/4GnT and C2/4GnT-active derivatives thereof are disclosed, in particular soluble derivatives comprising the catalytically active domain of C2/4GnT. Further, the invention discloses methods of obtaining 1,6-N-acetyl glucosaminyl glycosylated saccharides, glycopeptides or glycoproteins by use of an enzymically active C2/4GnT protein or fusion protein thereof or by using cells stably transfected with a vector including DNA encoding an enzymatically active C2/4GnT protein as an expression system for recombinant production of such glycopeptides or glycoproteins. Also a method for the identification for the identification of DNA sequence variations in the C2/4GnT gene by isolating DNA from a patient, amplifying C2/4GnT-coding exons by PCR, and detecting the presence of DNA sequence variation are disclosed.
一种新
基因定义了一种新型人类
UDP-GlcNAc:Gal/Gl cNAc&bgr; 1-3GalNAc a&bgr;1, 6GlcNAc-转移酶,称为 C2/4GnT,具有独特的酶学特性。C2/4GnT 的酶活性与以前发现的该
基因家族的酶不同。本发明公开了通过
氨基酸缺失、取代或插入的方式编码 C2/4GnT 及其衍
生物的分离 DNA 分子和 DNA 构建体,这些 DNA 分子和 DNA 构建体具有 C2/4GnT 的活性,本发明还公开了包括这种 DNA 的克隆和表达载体、用载体转染的细胞以及提供 C2/4GnT 的
重组方法。本发明公开了 C2/4GnT 酶及其 C2/4GnT 活性衍
生物,特别是包含 C2/4GnT 催化活性结构域的可溶性衍
生物。此外,本发明还公开了通过使用具有酶活性的 C2/4GnT 蛋白或其融合蛋白,或通过使用包括编码具有酶活性的 C2/4GnT 蛋白的 DNA 的载体稳定转染的细胞作为
重组生产此类糖肽或糖蛋白的表达系统,获得 1,6-N- 乙酰
葡糖胺基糖基化糖、糖肽或糖蛋白的方法。此外,还公开了一种用于鉴定 C2/4GnT
基因中 DNA 序列变异的方法,即从患者体内分离 DNA,通过 PCR 扩增 C2/4GnT 编码外显子,并检测是否存在 DNA 序列变异。