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用化学修饰法和底物保护法研究了大鼠肾脏３种Ｎ－乙酰氨基葡萄糖转移酶（ＧｎＴ）的必需基团，发现氨基和吲哚基为ＧｎＴ－ＩＩ、ＧｎＴ－ＩＶ和ＧｎＴ－Ｖ共同的必需基团，其中氨基可能参与和共同供体底物ＵＤＰ－ＧｌｃＮＡｃ的结合，吲哚基对ＧｎＴ－ＩＩ和ＧｎＴ－ＩＶ可能是受体底物——七糖糖链Ｇｎ２Ｍ３Ｇｎ２－ＰＡ的结合基团，而对ＧｎＴ－Ｖ可能是不参与底物结合的必需基团。胍基可能也参与ＧｎＴ－ＩＩ和供体底物结合，而对ＧｎＴ－ＩＶ和ＧｎＴ－Ｖ分别是不参与底物结合的必需基团以及不必需基团。羧基对ＧｎＴ－Ｖ可能参与和受体底物结合，而对ＧｎＴ－ＩＩ和ＧｎＴ－ＩＶ分别是不和底物结合的必需基团和不必需基团。此外，巯基、羟基和咪唑基对３种ＧｎＴ均为非必需基团。氨基糖对ＧｎＴ影响的研究也说明ＧｎＴ－ＩＩ和ＧｎＴ－Ｖ有不同的活性中心基团。
The necessary groups of three kinds of N-acetylglucosaminyltransferase (GnT) in rat kidneys were studied by chemical modification and substrate protection. The amino and indole groups were found to be GnT-II, GnT-IV and GnT-V Of which the amino group may be involved in the binding with the common donor substrate UDP-GlcNAc, the indolyl pairs GnT-II and GnT-IV may be the binding group of the acceptor substrate, the heptasaccharide chain Gn2M3Gn2-PA While GnT-V may not be necessary for the binding of substrates. Guanidinoids may also participate in the binding of GnT-II to donor substrates, whereas GnT-IV and GnT-V are essential and non-essential groups that do not participate in substrate binding, respectively. The carboxyl group GnT-V may be involved in binding to receptor substrates, whereas GnT-II and GnT-IV are essential and non-essential groups, respectively, that do not bind to the substrate. In addition, mercapto, hydroxyl and imidazolyl groups are all non-essential groups for all three GnTs. Studies of the effect of amino sugars on GnT also indicate that GnT-II and GnT-V have different active center groups.