A series of methoxy and deoxy derivatives of mannopyranose-1-phosphate (Manp-1P) were chemically synthesized, and their ability to be converted into the corresponding guanosine diphosphate mannopyranose (GDP-Manp) analogues by a pyrophosphorylase (GDP-ManPP) from Salmonella enterica was studied. Evaluation of methoxy analogues demonstrated that GDP-ManPP is intolerant of bulky substituents at the C-2, C-3, and C-4 positions, in turn suggesting that these positions are buried inside the enzyme active site. Additionally, both the 6-methoxy and 6-deoxy Manp-1P derivatives are good or moderate substrates for GDP-ManPP, thus indicating that the C-6 hydroxy group of the Manp-1P substrate is not required for binding to the enzyme. When taken into consideration with other previously published work, it appears that this enzyme has potential utility for the chemoenzymatic synthesis of GDP-Manp analogues, which are useful probes for studying enzymes that employ this sugar nucleotide as a substrate.
一系列甲氧基和去氧衍
生物的甘霖糖
吡喷酸酯(Man
p-1P)经
化学合成,研究了它们通过一种来自沙门氏菌(
Salmonella enterica)的
焦磷酸化酶(GDP-ManPP)能否转化为相应的
鸟苷二
磷酸甘霖糖(GDP-Man
p)类似物的能力。对甲氧基类似物的评价表明,GDP-ManPP对C-2、C-3和C-4位置的庞大取代基不耐受,进而暗示这些位置被埋藏在酶活性位点内部。此外,6-甲氧基和6-去氧 Man
p-1P 衍
生物均是GDP-ManPP的良好或中等底物,因此表明 Man
p-1P 底物的C-6 羟基不是与酶结合所必需的。综合考虑先前发表的其他研究成果,这种酶似乎具有潜在的用途,可用于化酶合成 GDP-Man
p 类似物,这些类似物是用于研究以这种糖核苷酸为底物的酶的有用探针。