The structure of siglec-7 in complex with sialosides: leads for rational structure-based inhibitor design
The structure of siglec-7 in complex with sialosides: leads for rational structure-based inhibitor design
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DOI：
10.1042/bj20060103
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发表时间：
2006-07-15
影响因子：
4.1
通讯作者：
van Aalten, Daan M. F.
中科院分区：
文献类型：
--
作者：
Attrill, Helen;Takazawa, Hirokazu;van Aalten, Daan M. F.
Siglecs（唾液酸结合igg样凝集素）是唾液化糖缀合物的跨膜受体，可调节造血、免疫和神经系统中的细胞相互作用和信号事件。siglec7是最近描述的免疫抑制cd33相关siglecs家族的结构原型，主要在自然杀伤细胞和单核细胞以及CD8 t细胞亚群上表达。siglecs特异性抑制剂用于检测被掩盖和未被掩盖的siglecs形式，以帮助解剖信号通路，并作为研究siglecs作为潜在治疗靶点的工具。作为实现这一目标的第一步，我们展示了siglece -7与唾液化配体(神经节苷脂类似物DSLc4 [α (2,3)/ α(2,6)二乙基乳四酰2-（三甲基硅基）乙基]的配合物的晶体结构，这可以详细描述结构导向抑制剂设计所需的结合位点。诱变和结合实验证明了Lys（131）的关键结构作用，这是一种在唾液酸结合时改变构象的残基。然后利用α -甲基Neu5Ac （n -乙酰神经氨酸）作为基本支架，利用siglec家族成员结合位点之间的差异。siglece -7配合物与唾液苷抑制剂oxamido-Neu5Ac[甲基α -9-（氨基-草酰-氨基）-9-脱氧neu5ac]的共晶和唾液苷的抑制数据为未来的抑制剂设计提供了明确的线索。
Siglecs (sialic acid binding Ig-like lectins) are transmembrane receptors for sialylated glycoconjugates that modulate cellular interactions and signalling events in the haematopoietic, immune and nervous systems. Siglec-7 is a structural prototype for the recently described family of immune inhibitory CD33-related siglecs and is predominantly expressed on natural killer cells and monocytes, as well as subsets of CD8 T-cells. Siglec-specific inhibitors are desired for the detection of masked and unmasked forms of siglecs, to aid in dissection of signalling pathways and as tools to investigate siglecs as potential therapeutic targets. As a first step towards this end, we present the crystal structure of siglec-7 in complex with a sialylated ligand, the ganglioside analogue DSLc4 [alpha(2,3)/alpha(2,6) disialyl lactotetraosyl 2-(trimethylsilyl)ethyl], which allows for a detailed description of the binding site, required for structure-guided inhibitor design. Mutagenesis and binding assays were used to demonstrate a key structural role for Lys(131), a residue that changes conformation upon sialic acid binding. Differences between the binding sites of siglec family members were then exploited using alpha-methyl Neu5Ac (N-acetylneuraminic acid) as a basic scaffold. A co-crystal of siglec-7 in complex with the sialoside inhibitor, oxamido-Neu5Ac [methyl alpha-9-(amino-oxalyl-amino)-9-deoxyNeu5Ac] and inhibition data for the sialosides gives clear leads for future inhibitor design.