STUDIES OF THREE TYPES OF GLYCOSYLTRANSFERASES

我们其中一个主要目标，是继续研究 新型糖基转移酶鉴定和性质研究 负责生物合成途径，这是不同的或相反的 目前公认的道路。例如，α（2，3）-唾液酸转移酶 其将作用于L-ex或甚至6 ′-磺基Le-x部分中的半乳糖 引起了我们的特别注意。alpha-L-的鉴定 能够将Le-x部分转化为Le-y残基的岩藻糖基转移酶 目标各种肿瘤细胞系和正常和癌性人类 组织是我们提议的源材料。我们计划尝试 新酶活性的纯化。 我们也将净化， 表征能够产生以下的β（1，3）-半乳糖基转移酶： Gal-beta1->3GlcNAc序列。该酶的特异性将在 详细的碳水化合物结构库。亲和层析 将作为我们纯化过程中的关键步骤几 可以存在α-L-岩藻糖基转移酶和唾液酸转移酶的类型，并且 我们建议继续研究 将详细研究这些酶，例如FT-VII的特异性。 含有唾液酸、硫酸盐和岩藻糖的糖缀合物吸引了 由于其作为潜在配体的近期重要性， 对于选择素，细胞粘附蛋白。我们计划进一步阐明 参与这种组装的生物合成途径 糖缀合物，特别是含有硫酸盐的O-连接的糖蛋白， 唾液酸和岩藻糖，例如GLYCAM-I，L-选择素的配体。的 继续这项计划将使我们能够填补各种空白， 我们对这些酶的特异性的认识仍然存在。 该计划一直是支持我们继续 在合成各种受体、修饰的碳水化合物 受体类似物和酶纯化所需的配体。我们 修饰的类似物将进一步检查它们作为 酶抑制剂对修饰受体类似物合成的兴趣 由于这些化合物被 有价值的工具，用于研究糖基化加工在体内和 体外已经为这种活体研究作出了合作安排。 同样，一个成功的计划结果将开辟各种途径， 其他重要的长期目标。例如，发现和 新特异性的糖基转移酶的文献可以使 开发独特的酶和免疫探针， 这些酶。

One of our main objectives is to continue our studies on the identification and characterization of new types of glycosyltransferases responsible for biosynthetic pathways which are different or contrary to the presently accepted pathways. For example, alpha(2,3)-sialyltransferase which will act upon galactose in L-ex or even 6'-sulfo Le-x moieties attracts our special attention. The identification of alpha-L- fucosyltransferase capable of converting the Le-x moiety to Le-y remains an objective. Various tumor cell lines and both normal and cancerous human tissues are our proposed source materials. We plan to attempt the purification of new enzyme activities. We will also purify and characterize the beta(1,3)-galactosyltransferase capable of generating the Gal-beta1->3GlcNAc sequence. Specificity of this enzyme will be studied in detail with a library of carbohydrate structures. Affinity chromatography will be employed as a key step in our purification procedures. Several types of alpha-L-fucosyltransferses and sialyltransferases can exist, and we propose to continue studies on the specificity and characterization of such enzymes, e.g. the specificity of FT-VII will be studied in detail. Glycoconjugates containing sialic acid, sulfate and fucose have attracted special attention due to their recent significance as potential ligands for selectins, the cell adhesion proteins. We plan to further elucidate the biosynthetic pathways involved in the assembly of such glycoconjugates, especially O-linked glycoproteins containing sulfate, sialic acid and fucose, e.g. GLYCAM-I, the ligand for L-selectin. The continuation of this program will allow us to fill in the various gaps that still exist in our knowledge of the specificity of these enzymes. This program has been the primary source of support for our continuing efforts at the synthesis of various acceptors, modified carbohydrate acceptor analogs, and ligands required for enzyme purification. Our modified analogs will be further examined for their potential use as enzyme inhibitors. Interest in the synthesis of modified acceptor analogs containing hydrophobic group is further enhanced as these compounds are valuable tools for the study of glycosylation processing in vivo and in vitro. Collaborative arrangements have been made for such studies in vivo. Similarly, a successful program outcome will open various avenues toward other important long term objectives. For example, the discovery and documentation of glycosyltransferases of novel specificities can enable the development of unique enzymatic and immunological probes to detect these enzymes.