作者: N J Galjart , N Gillemans , D Meijer , A d'Azzo
DOI: 10.1016/S0021-9258(19)39616-4
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摘要: The "protective protein" is the glycoprotein that forms a complex with lysosomal enzymes beta-galactosidase and neuraminidase. Its deficiency in man leads to metabolic storage disorder galactosialidosis. primary structure of human protective protein, deduced from its cloned cDNA, shows homology yeast serine carboxypeptidases. We have isolated full-length cDNA encoding murine protein. nucleotide sequences as well predicted amino acid are highly conserved between mouse. Domains important for protease function completely identical two proteins. Both mouse mature proteins covalently bind radiolabeled diisopropyl fluorophosphate. Transient expression COS-1 cells yields protein precursor 54 kDa, size characteristic glycosylated form. This cDNA-encoded precursor, endocytosed by galactosialidosis fibroblasts, processed into 32- 20-kDa heterodimer corrects neuraminidase activities. A tissue-specific mRNA observed when total RNA different organs analyzed on Northern blots.