The Human Alpha Mannosidase Full-length CDNA Cloning, Sequence Analysis And Protein-coding Nature

Majority of proteins is conjugated with carbohydrate to form glycoproteins in organism. The glycan in glycoprotein is not only related to the biological function of the protein, but also has important biological significance itself. Therefore, glycobiology is becoming an another prospecting area following protein and nuclear acid in the life science. Although the structure of the glycan is very complicated, which makes the study of its structure and function difficult, the advances in the knowledge and technique of molecular biology have greatly promoted the study.Alpha-mannosidase is an important one of the enzymes involved in the processing and maturation of N-linked glycans. In order to explore the action in the biosynthesis of glycan, more than ten cDNA clones of different alpha-mannosidase have been isolated from yeast and mammalian cells. Several years ago a 1358bp cDNA was cloned from a human tonsil cell λ gt11 cDNA library by using a monoclonal antibody 6A8 as a probe in our laboratory. An open reading frame encoding a 425 amino acid protein exists in the cDNA. The amino acid sequence of the protein deduced from the ORF is highly homologous to the c-terminal half of the amino acid sequence of a rat ER-alpha-mannosidase. The 1358bp cDNA sequence was registered in NIH GenBank data base in 1995 and called as 6A8 cDNA. Howevwe, no in frame stop codon was found before the start codon.In order to identify whether or not the 1358bp cDNA is...