Phosphorylcholine esterase is critical for Dolichos biflorus and Helix pomatia agglutinin binding to pneumococcal teichoic acid.
Phosphorylcholine esterase is critical for Dolichos biflorus and Helix pomatia agglutinin binding to pneumococcal teichoic acid.
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DOI：
10.1002/jobm.202000177
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发表时间：
2020-10
影响因子：
3.1
通讯作者：
Nahm MH
中科院分区：
文献类型：
--
作者：
Zhou ML;Frost MR;Xu YC;Nahm MH
肺炎链球菌（肺炎球菌）具有表达福斯曼抗原（FA）的壁磷壁酸（WTA）和脂磷壁酸（LTA）。已知两种凝集素，双花豆凝集素 (DBA) 和螺旋球菌凝集素 (HPA)，可结合 FA。为了确定这两种凝集素靶向的分子结构，利用流式细胞术和荧光显微镜研究了不同肺炎球菌菌株的 DBA/HPA 结合。基因实验被用来进一步检查凝集素的分子靶标。十二株 DBA 结合呈阳性，三株呈阴性。超分辨率显微镜显示 DBA 仅对肺炎球菌的荚膜下区域进行染色。三种DBA非结合剂在体外没有表现出磷酸胆碱酯酶（Pce）活性，而10种DBA结合剂表现出Pce活性（其余两种菌株是DBA结合剂，在体外没有Pce活性）。 10个代表性菌株的pce基因序列揭示了两个功能性pce等位基因，即先前识别的“等位基因A”和新发现的“等位基因B”（具有12个额外的核苷酸）。具有等位基因 B 的分离株在体外没有表现出 Pce 活性，但确实与 DBA 结合，表明等位基因 B Pce 在体内具有功能。遗传转移实验证实，任一等位基因对于 DBA 结合来说都是充分的（也是必要的）。三个 DBA 非结合者有各种影响 Pce 功能的突变。 HPA 的观察结果与 DBA 的观察结果相同。我们证明 DBA 和 HPA 仅与具有功能性 Pce 酶的肺炎球菌分离株的 WTA/LTA 结合。新发现的 Pce 变体（等位基因 B）在体内具有功能，但在体外检测时无效。
Streptococcus pneumoniae (the pneumococcus) has wall teichoic acid (WTA) and lipoteichoic acid (LTA) expressing the Forssman antigen (FA). Two lectins, Dolichos biflorus agglutinin (DBA) and Helix pomatia agglutinin (HPA), are known to bind FA. To determine the molecular structure targeted by these two lectins, different pneumococcal strains were studied for DBA/HPA binding with flow cytometry and fluorescence microscopy. Genetic experiments were used to further examine the lectins’ molecular target. Twelve strains were positive for DBA binding while three were negative. Super resolution microscopy showed that DBA stained only the subcapsular area of pneumococci. The three DBA non-binders showed no phosphorylcholine esterase (Pce) activity in vitro, whereas 10 DBA binders displayed Pce activity (the remaining two strains were DBA binders with no Pce activity in vitro). The pce gene sequence for 10 representative strains revealed two functional pce alleles, the previously recognized “allele A” and a newly-discovered “allele B” (with 12 additional nucleotides). Isolates with allele B showed no Pce activity in vitro but did bind to DBA, indicating allele B Pce is functional in vivo. Genetic transfer experiments confirmed that either allele is sufficient (and necessary) for DBA binding. The three DBA non-binders had various mutations that affected Pce function. Observations with HPA were identical to those with DBA. We show that DBA and HPA bind only to the WTA/LTA of pneumococcal isolates with a functional Pce enzyme. A newly-discovered Pce variant (allele B) is functional in vivo but nonfunctional when assayed in vitro.
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影响因子：
3
作者：
KELLENS, JTC;JACOBS, JA;STOBBERINGH, EE
通讯作者：
STOBBERINGH, EE
影响因子：
3.1
作者：
Spencer, Brady L.;Saad, Jamil S.;Nahm, Moon H.
通讯作者：
Nahm, Moon H.
影响因子：
2.9
作者：
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通讯作者：
KABAT, EA
影响因子：
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通讯作者：
Morrison, DA
影响因子：
4.7
作者：
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通讯作者：
Veening, Jan-Willem