ABSTRACT
We have developed a novel assay specific to MraY, which catalyzes the first membrane step in the biosynthesis of bacterial cell wall peptidoglycan. This was accomplished by using UDP-MurNAc-
N
ε
-dansylpentapeptide, a fluorescent derivative of the MraY nucleotide substrate, and a partially purified preparation of MraY solubilized from membranes of an
Escherichia coli
overproducing strain. Two versions of the assay were developed, one consisting of the high-pressure liquid chromatography separation of the substrate and product (dansylated lipid I) and the other, without separation and adapted to the high-throughput format, taking advantage of the different fluorescence properties of the nucleotide and lipid I in the reaction medium. The latter assay was validated with a set of natural and synthetic MraY inhibitors.
摘要
MraY 催化细菌细胞壁肽聚糖
生物合成过程中的第一个膜步骤。这是通过使用
UDP-MurNAc-
N
ε
-dansylpentapeptide(一种 MraY 核苷酸底物的荧光衍
生物)和从大肠杆菌膜中溶解的 MraY 的部分纯化制备物来完成。
大肠杆菌
的部分纯化制剂。我们开发了两种检测方法,一种是高压
液相色谱法分离底物和产物(丹参脂质 I),另一种是利用核苷酸和脂质 I 在反应介质中的不同荧光特性,无需分离,适合高通量格式。后一种检测方法用一组天然和合成的 MraY
抑制剂进行了验证。