STRUCTURE-FUNCTION RELATIONSHIPS OF LYSOSOMAL ENZYMES

说明了溶酶体酶--β-氨基己糖苷酶的重要性。 泰-萨克斯和桑德霍夫病是由基因突变引起的 ZYME的Alpha链和Beta链。在此之前，我们有 描述了该酶的正常生物合成途径和 泰-萨克斯病患者的这一通路中断。为了 在DNA水平上研究酶的正常和异常方面， 已经克隆了一个与Alpha链相对应的cDNA。使用Alpha链 NA Probe I筛选了在宇宙中构建的人类基因组文库 并分离出了几个含有该基因的克隆 Ne代表阿尔法链。这些克隆人正在被广泛地描述 限制性内切酶图谱、Southern杂交和DNA测序。到目前为止， 反式外显子组织的75%的20kb的阿尔法链基因已经 被终止了。这项工作将为 泰-萨克斯病基因突变的最终阐明。此外， 这第一个溶酶体酶基因的特征可能提供新的 观察这类重要的细胞糖蛋白。

e importance of the lysosomal enzyme, Beta-hexosaminidase, is illustrated Tay-Sachs and Sandhoff diseases which are caused by mutations in the zyme's Alpha and Beta chains, respectively. Previously, we had aracterized the normal biosynthetic pathway of the enzyme and the sruption of this pathway in patients with Tay-Sachs disease. In order to vestigate both normal and abnormal aspects of the enzyme at the DNA level, had cloned a cDNA corresponding to the Alpha-chain. Using Alpha-chain NA probes I have screened human genomic libraries constructed in cosmid and cteriophage lambda vectors and have isolated several clones containing the ne for the Alpha-chain. These clones are being extensively characterized restriction mapping, Southern blotting and DNA sequencing. Thus far, the tron-exon organization of 75% of the 20 kilobase Alpha-chain gene has been termined. This work will provide the informational framework for the entual elucidation of mutations in Tay-Sachs disease. In addition, the aracterization of this first lysosomal enzyme gene may provide novel sight into this important class of cellular glycoproteins.