Recognition of mannosylated ligands and influenza A virus by human surfactant protein D: contributions of an extended site and residue 343.
Recognition of mannosylated ligands and influenza A virus by human surfactant protein D: contributions of an extended site and residue 343.
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DOI：
10.1021/bi8022703
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发表时间：
2009-04-21
期刊：
影响因子：
2.9
通讯作者：
Head, James
中科院分区：
文献类型：
--
作者：
Crouch, Erika;Hartshorn, Kevan;Horlacher, Tim;McDonald, Barbara;Smith, Kelly;Cafarella, Tanya;Seaton, Barbara;Seeberger, Peter H.;Head, James
表面活性蛋白 D (SP-D) 在抗病毒宿主防御中发挥重要作用。尽管 SP-D 显示出对葡萄糖/麦芽糖的偏好，但该蛋白质也识别 D-甘露糖和各种富含甘露糖的微生物配体。后一种偏好促使人们对甘露糖识别机制进行了研究，特别是当它们与高甘露糖病毒聚糖相关时。来自人 SP-D (hNCRD) 的三聚颈+碳水化合物识别域优先选择 α1-2 连接的二甘露糖 (DM)，而不是支链三甘露糖 (TM) 核心、α1-3 或 α1-6 DM 或 D-甘露糖。先前的研究表明碳水化合物结合位点两侧的残基可以微调配体识别。与野生型和 R343A 相比，343 位具有缬氨酸的突变体 (R343V) 显示出与甘露聚糖的结合增强。未观察到 D-甘露糖或 α1-3 或 α1-6 连接 DM 的亲和力发生变化；然而，观察到 alpha1-2DM 的亲和力显着增加。两种蛋白质均显示出对碳水化合物微阵列上高甘露糖聚糖的线性和分支亚结构域的有效识别，并且 R343V 显示出与寡糖子集的结合增加。 R343V 与 1,2-DM 复合物的晶体学分析显示了一种新的结合模式。二糖通过还原糖环与钙结合，非还原糖环的2-OH与Arg349之间形成稳定的氢键。尽管hNCRD与甲型流感病毒（IAV）的结合可以忽略不计，但R343V却显示出显着增强的病毒中和活性。 Arg343 的疏水性取代选择性阻断单克隆抗体 (Hyb 246-05) 的结合，从而抑制 IAV 结合活性。我们的研究结果证明了甘露糖基化配体的扩展配体结合位点以及 343 侧链对多价微生物配体（包括高甘露糖病毒聚糖）的特异性识别的显着贡献。
Surfactant protein D (SP-D) plays important roles in antiviral host defense. Although SP-D shows a preference for glucose/maltose, the protein also recognizes D-mannose and a variety of mannose-rich microbial ligands. This latter preference prompted an examination of the mechanisms of mannose recognition, particularly as they relate to high-mannose viral glycans. Trimeric neck+carbohydrate recognition domains from human SP-D (hNCRD) preferred alpha1–2 linked dimannose (DM) over the branched trimannose (TM) core, alpha1–3 or alpha1–6 DM, or D-mannose. Previous studies have shown residues flanking the carbohydrate binding site can fine-tune ligand recognition. A mutant with valine at 343 (R343V) showed enhanced binding to mannan relative to wild-type and R343A. No alteration in affinity was observed for D-mannose or for alpha1–3 or alpha1–6 linked DM; however, substantially increased affinity was observed for alpha1–2DM. Both proteins showed efficient recognition of linear and branched sub-domains of high-mannose glycans on carbohydrate microarrays, and R343V showed increased binding to a subset of the oligosaccharides. Crystallographic analysis of an R343V complex with 1,2-DM showed a novel mode of binding. The disaccharide is bound to calcium by the reducing sugar ring, and a stabilizing H-bond is formed between the 2-OH of the non-reducing sugar ring and Arg349. Although hNCRDs show negligible binding to influenza A virus (IAV), R343V showed markedly enhanced viral neutralizing activity. Hydrophobic substitutions for Arg343 selectively blocked binding of a monoclonal antibody (Hyb 246-05) that inhibits IAV binding activity. Our findings demonstrate an extended ligand binding site for mannosylated ligands and the significant contribution of the 343 side chain to specific recognition of multivalent microbial ligands, including high-mannose viral glycans.
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影响因子：
4.8
作者：
Crouch, Erika;McDonald, Barbara;Head, James
通讯作者：
Head, James
影响因子：
2.7
作者：
Hartley, CA;Reading, PC;Anders, EM
通讯作者：
Anders, EM
DOI：
10.1107/s0907444998003254
发表时间：
1998-09-01
期刊：
ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY
影响因子：
--
作者：
Brunger, AT;Adams, PD;Warren, GL
通讯作者：
Warren, GL
DOI：
10.1152/ajplung.2000.278.1.l90
发表时间：
2000-01-01
影响因子：
4.9
作者：
Hartshorn, KL;Sastry, KN;Crouch, EC
通讯作者：
Crouch, EC
DOI：
10.1107/s0907444902016657
发表时间：
2002-11-01
影响因子：
2.2
作者：
Adams, PD;Grosse-Kunstleve, RW;Terwilliger, TC
通讯作者：
Terwilliger, TC