Organic Chemistry Institute, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149 Münster, Germany.
Beilstein J Org Chem. 2014 Jun 16;10:1354-64. doi: 10.3762/bjoc.10.138. eCollection 2014.
The molecular recognition of carbohydrates and proteins mediates a wide range of physiological processes and the development of synthetic carbohydrate receptors ("synthetic lectins") constitutes a key advance in biomedical technology. In this article we report a synthetic lectin that selectively binds to carbohydrates immobilized in a molecular monolayer. Inspired by our previous work, we prepared a fluorescently labeled synthetic lectin consisting of a cyclic dimer of the tripeptide Cys-His-Cys, which forms spontaneously by air oxidation of the monomer. Amine-tethered derivatives of N-acetylneuraminic acid (NANA), β-D-galactose, β-D-glucose and α-D-mannose were microcontact printed on epoxide-terminated self-assembled monolayers. Successive prints resulted in simple microarrays of two carbohydrates. The selectivity of the synthetic lectin was investigated by incubation on the immobilized carbohydrates. Selective binding of the synthetic lectin to immobilized NANA and β-D-galactose was observed by fluorescence microscopy. The selectivity and affinity of the synthetic lectin was screened in competition experiments. In addition, the carbohydrate binding of the synthetic lectin was compared with the carbohydrate binding of the lectins concanavalin A and peanut agglutinin. It was found that the printed carbohydrates retain their characteristic selectivity towards the synthetic and natural lectins and that the recognition of synthetic and natural lectins is strictly orthogonal.
碳水化合物与蛋白质的分子识别介导了广泛的生理过程，而合成碳水化合物受体（“合成凝集素”）的发展则是生物医学技术的重要进步。在本文中，我们报告了一种能够选择性结合固定在分子单层中的碳水化合物的合成凝集素。受我们之前工作的启发，我们制备了一种荧光标记的合成凝集素，它由三肽 Cys-His-Cys 的环状二聚体组成，该二聚体通过单体的空气氧化自发形成。N-乙酰神经氨酸（NANA）、β-D-半乳糖、β-D-葡萄糖和α-D-甘露糖的胺键合衍生物被微接触印刷在环氧化物封端的自组装单层上。连续的印刷导致了两种碳水化合物的简单微阵列。通过在固定化碳水化合物上孵育来研究合成凝集素的选择性。通过荧光显微镜观察到合成凝集素对固定化 NANA 和β-D-半乳糖的选择性结合。通过竞争实验筛选了合成凝集素的选择性和亲和力。此外，还比较了合成凝集素与凝集素伴刀豆球蛋白 A 和花生凝集素的碳水化合物结合。结果发现，印刷的碳水化合物保留了它们对合成和天然凝集素的特征选择性，并且合成和天然凝集素的识别是严格正交的。
