STUDIES OF THREE TYPES OF GLYCOSYLTRANSFERASES

我们的主要目标之一是继续研究 新型糖基转移酶的鉴定和性质研究 负责不同或相反的生物合成途径 目前被接受的路径。例如，α(2，3)-唾液酸基转移酶 它将作用于L-EX或甚至6‘-磺酸基Le-x中的半乳糖 引起了我们的特别关注。阿尔法-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 一个目标。各种肿瘤细胞系和正常人和癌变的人 组织是我们建议的来源材料。我们计划尝试 新酶活性的纯化。我们还将净化和 鉴定β(1，3)-半乳糖基转移酶能够产生 Gal-beta1-&gt；3GlcNAc序列。这种酶的专一性将在 详细介绍了碳水化合物结构的库。亲和层析 将被用作我们提纯程序中的关键步骤。几个 可以存在α-L岩藻糖基转移酶和唾液酸基转移酶类型，以及 我们建议继续研究其特异性和特征。 这类酶，例如FT-VII的专一性，将被详细研究。 含有唾液酸、硫酸盐和岩藻糖的糖偶联物吸引了 由于它们最近作为潜在配体的重要性而受到特别关注 对于选择素，细胞黏附蛋白。我们计划进一步澄清 参与这种物质组装的生物合成途径 糖偶联物，尤指含有硫酸盐的O-连接糖蛋白， 唾液酸和岩藻糖，如L-选择素的配体GLYCAM-I。这个 这一计划的继续将使我们能够填补各种空白 仍然存在于我们对这些酶的专一性的了解中。 该计划一直是我们继续 努力合成各种受体，修饰的碳水化合物 受体类似物，以及酶纯化所需的配体。我们的 修改后的类似物将被进一步研究其潜在用途 酶抑制剂。对修饰受体类似物的合成感兴趣 含有疏水基团的化合物随着这些化合物被 体内和体内糖基化过程研究的有价值的工具 体外培养。已经为活体内的这种研究做出了合作安排。 同样，一个成功的项目成果将开辟各种途径，从而 其他重要的长期目标。例如，发现和 记录新的特异性的糖基转移酶可以使 检测酶学和免疫学的独特探针的研制 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.