ISOLATION OF OLIGOSACCHARIDES--SUGAR-BINDING PROTEINS

碳水化合物与许多生理上重要的细胞 表面功能包括细胞-细胞识别、生长控制和 毒素和糖蛋白激素的受体。 中的困难 获得足够的数量和确定有限的结构， 生理上重要的细胞表面寡糖的量是 缺乏关于涉及哪些结构的知识的主要原因 在这些过程中。 由于人乳中的游离低聚糖含有 在细胞表面糖脂中也发现了这种结构， 寡糖可用于灵敏的放射免疫测定， 复杂生物样品中的特定碳水化合物。 由于化学方法用于异常结构分析， 低聚糖，诊断某些疾病和遗传性疾病， 它们的代谢需要费力的纯化和昂贵的 仪器，它们一般不适用于筛查、诊断 或疾病分类。 放射免疫分析用于诊断 重要的寡糖可能是有价值的替代物。 为基础 在本申请中，抗人寡糖的特异性抗血清将 应用于人胎粪中神经节苷脂的分析， 诊断标本和丰富的胎儿糖脂来源。 结合125 I标记的碳水化合物特异性的细胞表面糖脂 抗体、霍乱毒素、凝集素和其他生理上重要的 糖结合蛋白可在薄层色谱图上检测到 通过灵敏的放射自显影技术。 释放的寡聚体 功能性糖脂可以通过用NaB[3 H]4还原来标记， 通过放射免疫结合方法从复杂混合物中分离。 结构 使用特异性抗寡糖抗体和特异性 外切糖苷酶消化将是鉴定次要的， 细胞表面碳水化合物结构。 这些方法还将 应用于血型特异性凝集素的表征， 抗体及其相应的糖脂同种抗原。

Carbohydrates have been implicated in many physiologically important cell surface functions including cell-cell recognition, growth control and receptors for toxins and glycoprotein hormones. The difficulties in obtaining sufficient amounts and determining the structure of the limited quantities of physiologically important cell surface oligosaccharides are major reasons for the lack of knowledge about what structures are involved in these processes. Since free oligosaccharides in human milk contain structures also found in cell surface glycolipids, antibodies against these oligosaccharides can be used in sensitive radioimmunoassays to detect specific carbohydrates in complex biological samples. Since chemical methods for structural analyses of abnormal oligosaccharides, diagnostic for certain diseases and genetic disorders of their metabolism, require laborious purification and expensive instrumentation, they are generally not applicable to screening, diagnosis or classification of diseases. Radioimmunoassays for diagnostically important oligosaccharides may be a valuable alternative. As a basis for this application, specific antisera against human oligosaccharides will be applied to the ganglioside analysis of human meconium, a potential diagnostic specimen and a rich source of fetal glycolipids. Cell surface glycolipids that bind 125I-labeled carbohydrate-specific antibodies, cholera toxin, lectins and other physiologically important carbohydrate-binding proteins can be detected on thin layer chromatograms by sensitive autoradiographic techniques. Oligosaccharides released from functional glycolipids can be labeled by reduction with NaB[3H]4 and isolated from complex mixtures by radioimmune-binding methods. Structural analyses using specific anti-oligosaccharide antibodies and specific exoglycosidase digestion will be fundamental to identifying minor, functional cell surface carbohydrate structures. These methods will also be applied to the characterization of blood group specific lectins and antibodies and their corresponding glycolipid isoantigens.