Identification and functional analysis of a galactosyltransferase capable of cholesterol glycolipid formation in the Lyme disease spirochete Borrelia burgdorferi.
Identification and functional analysis of a galactosyltransferase capable of cholesterol glycolipid formation in the Lyme disease spirochete Borrelia burgdorferi.
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DOI：
10.1371/journal.pone.0252214
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发表时间：
2021
期刊：
影响因子：
3.7
通讯作者：
Belisle JT
中科院分区：
文献类型：
--
作者：
Hove PR;Magunda F;de Mello Marques MA;Islam MN;Harton MR;Jackson M;Belisle JT
伯氏疏螺旋体是莱姆病的病原体，它能产生一系列简单的糖脂，其中二酰甘油和胆固醇是前体。以胆固醇为基础的糖脂，胆固醇6-O-酰基-β-D-半乳糖苷(ACGal)和胆固醇-β-D-半乳糖苷(CGAL)具有免疫原性，被认为与莱姆病的发病有关。由于缺乏对其潜在生物合成过程的了解，对CGal和ACGal在BB中的详细研究一直受到阻碍。Bb基因组编码4种糖基转移酶，其中只有BB0572被预测为能以半乳糖为底物形成β-糖苷键的糖基转移酶。与其它疏螺旋体的42 kDa BB0572氨基酸序列比较表明，该蛋白高度保守。为了确定BB0572是Bb中能够形成胆固醇糖脂的半乳糖基转移酶，在大肠杆菌中以重组产物的形式表达BB0572，并以14C-胆固醇和UDP-半乳糖为底物进行了无细胞实验。本实验得到了一种放射性标记的脂质，当用薄层层析法评估时，它与CGal的胆固醇糖脂标准迁移。此外，BB0572预测活性部位的突变导致重组蛋白不能催化胆固醇糖脂的形成。这些数据表明BB0572可能是一种胆固醇半乳糖基转移酶。这为了解BB胆固醇糖脂是如何形成的提供了第一步，并将使对它们参与病原体传播和疾病发展的研究成为可能。
Borrelia burgdorferi (Bb), the etiological agent of Lyme disease, produces a series of simple glycolipids where diacylglycerol and cholesterol serve as the precursor. The cholesterol-based glycolipids, cholesteryl 6-O-acyl-β-D-galactopyranoside (ACGal) and cholesteryl-β-D-galactopyranoside (CGal) are immunogenic and proposed to contribute to the pathogenesis of Lyme disease. Detailed studies of CGal and ACGal in Bb have been hampered by a lack of knowledge of their underlying biosynthetic processes. The genome of Bb encodes four putative glycosyltransferases, and only one of these, BB0572, was predicted to be an inverting family 2 glycosyltransferase (GT2 enzyme) capable of using UDP-galactose as a substrate and forming a β-glycosidic bond. Comparison of the 42 kDa BB0572 amino acid sequence from Bb with other Borrelia spp demonstrates that this protein is highly conserved. To establish BB0572 as the galactosyltransferase capable of cholesterol glycolipid formation in Bb, the protein was produced as a recombinant product in Escherichia coli and tested in a cell-free assay with 14C-cholesterol and UDP-galactose as the substrates. This experiment resulted in a radiolabeled lipid that migrated with the cholesterol glycolipid standard of CGal when evaluated by thin layer chromatography. Additionally, mutation in the predicted active site of BB0572 resulted in a recombinant protein that was unable to catalyze the formation of the cholesterol glycolipid. These data characterize BB0572 as a putative cholesterol galactosyltransferase. This provides the first step in understanding how Bb cholesterol glycolipids are formed and will allow investigations into their involvement in pathogen transmission and disease development.
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影响因子：
6.7
作者：
Crowley JT;Toledo AM;LaRocca TJ;Coleman JL;London E;Benach JL
通讯作者：
Benach JL
影响因子：
3.1
作者：
Liang, FT;Yan, J;Fikrig, E
通讯作者：
Fikrig, E
影响因子：
3.1
作者：
LIVERMORE, BP;BEY, RF;JOHNSON, RC
通讯作者：
JOHNSON, RC
DOI：
10.1016/0005-2760(80)90213-1
发表时间：
1980-01-01
期刊：
BIOCHIMICA ET BIOPHYSICA ACTA
影响因子：
--
作者：
KASTELICSUHADOLC, T
通讯作者：
KASTELICSUHADOLC, T
影响因子：
3.2
作者：
HIRAI, Y;HAQUE, M;OGUMA, K
通讯作者：
OGUMA, K