Garbarino Emanuela, Subbiahdoss Guruprakash, Scheberl Andrea, Reimhult Erik, Misevic Gradimir
Department of Immunology, Nanjing Medical University, 101 Longmian Avenue, Jiangning District, Nanjing, 211166, PR China.
Institute of Colloid and Biointerface Science, Department of Bionanosciences, BOKU University, Muthgasse 11/II, 1190, Vienna, Austria.
Commun Biol. 2024 Dec 19;7(1):1677. doi: 10.1038/s42003-024-07355-3.
Mucin, proteoglycan, glyconectin, and hyaluronan intermolecular binding in the physiological hydrated state forms the native glycocalyx ultrastructure via the polyvalent interactions of their similar bottle-brush morphologies. This ultrastructure provides a variety of essential cellular recognition/adhesion and selective filtration functions. Unfortunately, for decades, the glycocalyx architecture was only examined in the non-native dehydrated/fixed state. This has resulted in the visualization of an artefactual unorganized fiber mesh, hindering understanding of structure-function relationships. We unveil a well-organized glycocalyx lamellar ultrastructure using cryo-SEM after cryo-preservation with minimal sublimation to conserve water and ion distribution and, thereby, native intermolecular interactions. The glycocalyx of human cells and the glyconectin glycocalyx of an evolutionary distant sponge displayed similar self-assembled ultrastructures comprising hierarchical micro- and nanoarrays despite compositional differences. AFM binding strength measurements and cryo-SEM results imply that evolutionarily preserved glycocalyx morphologies are formed by thermodynamically driven self-assembly of glycoconjugates with similar physicochemical properties.
在生理水合状态下，黏蛋白、蛋白聚糖、糖结合蛋白和透明质酸的分子间结合通过其相似的刷状形态的多价相互作用形成天然糖萼超微结构。这种超微结构提供了多种重要的细胞识别/黏附以及选择性过滤功能。不幸的是，几十年来，糖萼结构仅在非天然的脱水/固定状态下进行研究。这导致了一种人为的无组织纤维网的可视化，阻碍了对结构-功能关系的理解。我们通过低温扫描电子显微镜（cryo-SEM）揭示了一种组织良好的糖萼层状超微结构，该结构是在经过低温保存且升华极少以保留水和离子分布从而保留天然分子间相互作用之后得到的。尽管组成不同，但人类细胞的糖萼和进化上距离较远的海绵的糖结合蛋白糖萼显示出相似的自组装超微结构，包括分层的微米和纳米阵列。原子力显微镜（AFM）结合强度测量和低温扫描电子显微镜结果表明，进化上保留的糖萼形态是由具有相似物理化学性质的糖缀合物通过热力学驱动的自组装形成的。
