Chemically tunable mucin chimeras assembled on living cells
Chemically tunable mucin chimeras assembled on living cells
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DOI：
10.1073/pnas.1516127112
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发表时间：
2015-10-13
影响因子：
11.1
通讯作者：
Bertozzi, Carolyn R.
中科院分区：
文献类型：
--
作者：
Kramer, Jessica R.;Onoa, Bibiana;Bertozzi, Carolyn R.
粘蛋白是分泌型跨膜糖蛋白家族，其特征是丝氨酸和苏氨酸残基上有大量密集的 O-糖基化结构域。粘蛋白与免疫和癌症密切相关，但其糖结构域的生物学作用的阐明因其巨大的尺寸、结构域多态性和可变的糖基化模式而变得复杂。在这里，我们开发了一种通过 N-羧酸酐聚合来合成成分明确的、高分子量的、双末端功能化的粘蛋白糖结构域构建体库的合成路线。这些糖多肽是我们所知的第一个合成类似物，具有天然 a-GalNAc 与丝氨酸的连接，其分子量与天然粘蛋白相似，解决了近 50 年的合成难题。模拟物的物理表征揭示了对粘蛋白结构和特性的见解。合成的糖结构域用光学探针和四嗪部分进行末端功能化，从而允许与活哺乳动物细胞上的工程膜蛋白进行位点特异性生物正交缀合。这种蛋白质工程策略将为探索细胞表面粘蛋白的生物学作用开辟途径。
Mucins are a family of secreted and transmembrane glycoproteins characterized by a massive domain of dense O-glycosylation on serine and threonine residues. Mucins are intimately involved in immunity and cancer, yet elucidation of the biological roles of their glycodomains has been complicated by their massive size, domain polymorphisms, and variable glycosylation patterns. Here we developed a synthetic route to a library of compositionally defined, high-molecular weight, dual end-functionalized mucin glycodomain constructs via N-carboxyanhydride polymerization. These glycopoly-peptides are the first synthetic analogs to our knowledge to feature the native a-GalNAc linkage to serine with molecular weights similar to native mucins, solving a nearly 50-year synthetic challenge. Physical characterization of the mimics revealed insights into the structure and properties of mucins. The synthetic glycodomains were end-functionalized with an optical probe and a tetrazine moiety, which allowed site-specific bioorthogonal conjugation to an engineered membrane protein on live mammalian cells. This strategy in protein engineering will open avenues to explore the biological roles of cell surface mucins.