作者:M. Carmen Galan、Andre P. Venot、John Glushka、Anne Imberty、Geert-Jan Boons
DOI:10.1039/b308559g
日期:——
macrocyclization by nucleophilic displacement of the chloride by a C-2' hydroxyl. The conformational properties of 4 were determined by a combination of NOE and trans-glycosidic heteronuclear coupling constant measurements and molecular mechanics simulations and these studies established that the glycosidic linkage of 4 is conformationally constrained and resides in only one of the several energy minima accessible
使用大鼠肝脏的α-2,6-唾液酸转移酶(ST6GalI)或重组人岩藻糖基转移酶V(FucT-V)对N-乙酰氨基胺衍生物4(在C-6和C-2'之间具有亚甲基酰胺系链)进行糖基化分别受构象约束的三糖5和6。通过两步程序安装4的亚甲酰胺接头,该步骤涉及用氯乙酸酐对LacNAc衍生物的C-6氨基官能团进行酰化,然后通过C-2'羟基的氯化物亲核置换进行大环化。通过结合NOE和反式糖苷异核偶联常数测量以及分子力学模拟确定4的构象性质,这些研究确定4的糖苷键受到构象约束,并且仅存在于LacNAc可访问的几个最小能量中的一个。 。转移至LacNAc以及构象受限的糖3和4的表观动力学参数表明,岩藻糖基转移酶V在其A构象异构体中识别LacNAc,而α-2,6-唾液酸基转移酶识别LacNAc的B构象异构体。