摘要
Bovine galactosyl transferase was found to utilize UDPglucose as a substrate and elicit disaccharide biosynthesis with glucose and N-acetylglucosamine as acceptors. The relative rate of glycosyl transferase with N-acetylglucosamine as acceptor was 0.3%, the rate for N-acetyllactosamine biosynthesis. This activity was also evidenced indirectly from NMR water proton relaxation experiments, and from Mn(II) ESR experiments. In direct experiments with radioactive UDPglucose, paper chromatography showed a product which migrated with cellobiose when glucose was the acceptor and a new, glucose-containing product which resulted when GlcNAc was the acceptor.
Despite this marginally expanded specificity of the donor site, spin-label experiments with a covalently bound UDPgalactose analog reaffirmed the restrictive nature of the donor site against this non-glycosyl-like analog.
摘要译文
发现牛半乳糖基转移酶利用UDP葡萄糖作为底物并引发葡萄糖和N-乙酰葡糖胺作为受体的二糖生物合成。糖基转移酶与N-乙酰葡糖胺作为受体的相对比率为0.3％，即N-乙酰基乳糖胺生物合成的速率。这种活性也通过NMR水质子弛豫实验和Mn（II）ESR实验间接证明。在放射性UDP葡萄糖的直接实验中，纸色谱显示当葡萄糖是受体时与纤维二糖一起迁移的产物和当GlcNAc是受体时产生的新的含葡萄糖的产物。尽管供体位点的这种略微扩展的特异性，用共价结合的UDP半乳糖类似物进行的自旋标记实验再次证实了供体位点对这种非糖基类似物的限制性质。
PietJan Andree[∗];Lawrence J.Berliner;. Glucosyl transferase activity of bovine galactosyl transferase[J]. Biochimica et Biophysica Acta (BBA) - General Subjects, 1978,544(3): 489-495