Takeya A, Hosomi O, Kogure T
Jpn J Med Sci Biol. 1985 Feb;38(1):1-8.
Normal human urine was found to contain beta (1-3)N-acetylglucosaminyltransferase catalyzing the transfer of N-acetylglucosamine from UDP-GlcNAc to N-acetyllactosamine and lactose. Lacto-N-tetraose which carries the terminal Gal beta (1-3)GlcNAc structure was a poor acceptor. The product of the transferase reaction with N-acetyllactosamine as acceptor was identified by methylation analysis as GlcNAc beta (1-3)Gal beta (1-4)GlcNAc. The beta-linkage of the GlcNAc in the synthesized trisaccharide was confirmed by the action of the specific beta-N-acetylhexosaminidase. The enzyme requires Mn2+ ions for its activity, shows a broad pH optimum from 7 to 9, and appears to have a molecular weight of about 200,000 as estimated by Sephadex gel filtration.
研究发现，正常人尿液中含有β(1-3)N-乙酰葡糖胺基转移酶，该酶可催化N-乙酰葡糖胺从UDP-GlcNAc转移至N-乙酰乳糖胺和乳糖。带有末端Galβ(1-3)GlcNAc结构的乳糖-N-四糖是较差的受体。以N-乙酰乳糖胺作为受体时，转移酶反应的产物经甲基化分析鉴定为GlcNAcβ(1-3)Galβ(1-4)GlcNAc。合成三糖中GlcNAc的β-连接通过特异性β-N-乙酰己糖胺酶的作用得以证实。该酶的活性需要Mn2+离子，在pH 7至9范围内表现出较宽的最适pH值，通过葡聚糖凝胶过滤法估计其分子量约为200,000。
