THREE TYPES OF GLYCOSYLTRANSFERASES

我们的主要目标是识别和描述新类型的 负责生物合成途径的糖基转移酶 与当前接受的途径不同或相反。我们计划 能结合岩藻糖的α(1，2)-L岩藻糖基转移酶的鉴定 在X-行列式(Le(X))中半乳糖的C-2位 结构，Galbeta1得到4(Fucalpha1得到3)GlcNAc，从而给出 LE(Y)序列，Fucalpha1得2 Galbeta1得4(Fucalpha1得 3)GlcNAcbeta1产生OR。同样，我们计划研究阿尔法(2，3)- 唾液酸基转移酶可以使用Le(X)和Le(A)结构作为 接受者。最近，我们分离并部分表征了 β(1-3)-半乳糖基转移酶，将半乳糖结合到 R-GlcNAcbeta1中的Alpha连接的GalNAc残基产生6 GalNAcalpha1 得到OB序列得到R-GlcNAcbeta1得到6(Galbeta1得到3) GalNAcalpha1产生OR(核心II结构)。我们感兴趣的是 利用不同的肿瘤细胞系和正常和癌 人体组织作为我们研究的来源材料。我们还将 试图纯化其中一些新的酶活性，如 作为β(1，3)-半乳糖基转移酶和α(1，3)-L岩藻糖基转移酶 存在于人肺癌细胞系中。亲和层析 将被用作这些净化的关键步骤。两个核苷酸 并将为此提供特定的受体配体 技术。 我们的化学合成方法将主要用于 采购各种明确定义的碳水化合物结构 研究这些酶所必需的，包括受体和 配基。某些独特且高度特定的接受者部分可以是 以使我们能够检查单个 糖基转移酶活性，尽管存在其他 糖基转移酶存在于同一来源。我们还打算 评估我们的一些修改的类似物作为某些特定的抑制剂 糖基转移酶活性。 新类型糖基转移酶活性的鉴定将 更多地揭示了糖结合物的生物合成途径， 尤其是含有Le(X)、Le(A)和 Sialyl(Le(X)和Le(A))行列式。我们打算通过这项研究 以填补我们在对特定性的认识中存在的各种空白 建议研究的这些酶中。一个成功的结果 拟议的计划将为其他长期计划开辟各种途径 目标。例如，糖基的发现和记录- 新奇特异性的转移酶可以使 独特的酶和免疫学探针来检测这些酶。

Our primary objective is to identify and characterize new types of glycosyltransferases responsible for biosynthetic pathways which are different or reverse to the currently accepted pathways. We plan to identify alpha(1,2)-L-fucosyltransferase which can incorporate fucose at the C-2 position of galactose in the X-determinant (Le(x)) structure, Galbeta1 yields 4 (Fucalpha1 yields 3) GlcNAc, to give the Le(y) sequence, Fucalpha1 yields 2 Galbeta1 yields 4 (Fucalpha1 yields 3) GlcNAcbeta1 yields OR. Similarly, we plan to study the alpha (2,3)- sialyltransferases which can use Le(x) and Le(a) structures as acceptors. Recently, we have isolated and partially characterized beta(1-3)-galactosyltransferase which incorporates galactose to the alpha-linked GalNAc residue in the R-GlcNAcbeta1 yields 6 GalNAcalpha1 yields OB sequence to give R-GlcNAcbeta1 yields 6 (Galbeta1 yields 3) GalNAcalpha1 yields OR (Core II structure). We are interested in utilizing different tumor cell lines and both normal and cancerous human tissues as source material for our investigations. We will also attempt to purification of some of these new enzyme activities, such as beta(1,3)-galactosyltransferase and alpha(1,3)-L-fucosyltransferase present in human lung carcinoma cell lines. Affinity chromatography will be employed as a key step in these purifications. Both nucleotide and specific-acceptor ligands will be made available for this technique. Our chemical synthetic approach will be primarily used for the procurement of the variety of well-defined carbohydrate structures required for the study of these enzymes, including acceptors and ligands. Certain unique and highly specific acceptor moieties can be provided to enable us to examine the activity of a single glycosyltransferase activity in spite of the presence of other glycosyltransferases present in the same source. We also intend to evaluate some of our modified analogs as inhibitors of certain glycosyltransferase activities. The identification of new types of glycosyltransferase activities will shed more light on the biosynthetic pathways of glycoconjugates, especially fucosylated glycoconjugates containing Le(x), Le(a) and sialyl (Le(x) and Le(a)) determinants. We intend through this research to fill the various gaps that exist in our knowledge of the specificity of those enzymes proposed for study. A successful outcome of the proposed program will open various avenues toward other long-term objectives. For example, the discovery and documentation of glycosyl- transferases of novel specificities can enable the development of unique enzymatic and immunological probes to detect these enzymes.