SYSTEMATIC STUDY OF THREE TYPES OF GLYCOSYLTRANSFERASES

这是强烈建议，改变水平和 糖基转移酶的特异性可能会导致 细胞表面糖缀合物的碳水化合物组成。 在 近年来，一些糖基转移酶作用于 因为肿瘤标志物已经变得明显。 在这个节目中， 集中精力研究人岩藻糖、半乳糖 和唾液酸转移酶。 定义明确的碳水化合物结构是 糖基转移酶研究的重要工具，我们计划 继续使用一系列碳水化合物， 确定这些酶的特异性。 从糖核苷酸供体到糖核苷酸供体的糖苷键可以是糖核苷酸供体的糖苷键。 受体，由催化反应形成的 糖基转移酶，将通过各种程序建立 其还包括使用特定的糖苷酶。 我们 合成能力还提供了用于 确定酶促产物的结构。 我们计划阐明某些肿瘤的生物合成途径- 相关抗原，例如具有Lex决定簇的糖缀合物， 唾液酸化的Lex决定簇，我们的合成片段， 作为这类抗原的一部分发生起着关键作用。 我们的特性 肿瘤组织和正常组织糖基转移酶的研究 将使我们能够看到，如果酶从肿瘤组织有广泛的 特异性或不特异性 此外，我们的调查应该会导致 一种特异性受体的发现， 糖基转移酶和我们的合成修饰类似物将是 可用于测定单一类型的糖基转移酶。 利用这种特异性和独特的受体， 健康个体的血清或唾液中的糖基转移酶，以及 将对癌症患者的样本进行检查。 准确地说， 该计划提供了一个系统的方法，主要是为 三种类型的糖基转移酶的生化研究， 仅包括所选酶活性的纯化。

It is strongly suggested that alteration in the levels and specificity of glycosyltransferase may cause alterations in the carbohydrate composition of cell surface glycoconjugates. In recent years the possibility of some glycosyltransferases acting as tumor markers has become apparent. In this program we have been concentrating our efforts on the study of human fucosyl, galactosyl and sialyltransferases. Well-defined carbohydrate structures are important tools for the study of glycosyltransferases and we plan to continue to employ a series of carbohydrate compounds to determine the specificity of these enzymes. The glycosidic linkage from a sugar nucleotide donor to the acceptor, formed by the catalytic reaction of a glycosyltransferase, will be established by various procedures which also includes the use of specific glycosidases. Our synthetic capability also provides reference compounds for confirming the structure of enzymatic products. We plan to elucidate the biosynthetic pathway of certain tumor- associated antigens, e.g. glycoconjugates with Lex determinants and sialylated Lex determinants, whereby our synthetic fragments which occur as a part of such antigens play a key role. Our specificity studies on glycosyltransferase from tumor tissue and normal tissue will enable us to see if the enzymes from tumor tissue have broad specificity or not. Moreover, our investigations should lead to the discovery of a highly specific acceptor for a specific type of glycosyltransferase and our synthetic modified analogs will be useful for the assay of a single type of glycosyltransferase. Utilizing such specific and unique acceptors, levels of the glycosyltransferase in sera or saliva of healthy individuals and in specimens from cancer patients will be examined. Precisely, this program provides a systematic approach primarily for the biochemical studies of three types of glycosyltransferases and purification of only selected enzyme activities are included.