Nanba E, Suzuki K
Department of Neurology, University of North Carolina School of Medicine, Chapel Hill 27599.
Biochem Biophys Res Commun. 1990 Nov 30;173(1):141-8. doi: 10.1016/s0006-291x(05)81033-2.
A full-length cDNA coding for mouse lysosomal acid beta-galactosidase has been isolated on the basis of homology with the human gene. Catalytic activity toward 4-methylumbelliferyl beta-D-galactoside in the COS-1 cell expression system provided positive proof for its authenticity. The sequence analysis showed that the degree of similarity between the human and mouse enzymes was approximately 70% in the nucleotide sequence and nearly 80% in the amino acid sequence. The deduced primary amino acid sequences of the enzymes from the two species indicated that, of the seven possible N-glycosylation sites in the human enzyme, five are conserved in the mouse enzyme. Three additional possible N-glycosylation sites, not present in the human enzyme, are found in the primary amino acid sequence of the mouse enzyme. All seven cysteine residues in the mouse enzyme are conserved in the human enzyme. Although the nucleotide sequence could be aligned to 60% identity with the E. coli beta-galactosidase, similarity in the amino acid sequence was minimal.
基于与人类基因的同源性，已分离出编码小鼠溶酶体酸性β-半乳糖苷酶的全长cDNA。在COS-1细胞表达系统中对4-甲基伞形酮基β-D-半乳糖苷的催化活性为其真实性提供了确凿证据。序列分析表明，人类和小鼠酶之间的核苷酸序列相似度约为70%，氨基酸序列相似度近80%。两种物种酶的推导一级氨基酸序列表明，人类酶中七个可能的N-糖基化位点中有五个在小鼠酶中保守。在小鼠酶的一级氨基酸序列中发现了人类酶中不存在的另外三个可能的N-糖基化位点。小鼠酶中的所有七个半胱氨酸残基在人类酶中均保守。尽管核苷酸序列与大肠杆菌β-半乳糖苷酶的一致性可达到60%，但氨基酸序列的相似性很小。
