lysosomal alpha-mannosidase; alpha B mannosidase; laman; lysosomal acid alpha-mannosidase; mannosidase alpha class 2B member 1; mannosidase, alpha B [contains: full=lysosomal alpha-mannosidase A peptide; lysosomal alpha-mannosidase B peptide; lysosomal alpha-mannosidase C peptide; lysosomal alpha-mannosidase D peptide; lysosomal alpha-mannosidase E peptide] (MAN2B1, LAMAN, MANB)

Function

• necessary for the catabolism of N-linked carbohydrates
• released during glycoprotein turnover
• cleaves all known types of alpha-mannoside linkages
• 1ST processed into 3 peptides of 70 kD, 42 kD (D) & 13/15 kD (E)
  • the 70 kD peptide is further processed into three peptides (A, B & C)
  • the A, B & C peptides are disulfide-linked
• hydrolysis of terminal, non-reducing alpha-D-mannose residues in alpha-D-mannosides

Cofactor: binds 1 Zn+2 per subunit (putative)

Structure

• heavily glycosylated
• belongs to the glycosyl hydrolase 38 family

Compartment

lysosome

Pathology

• defects in MAN2B1 are the cause of lysosomal alpha-mannosidosis

Laboratory

• MAN2B1 gene mutation

More general terms

• alpha-mannosidase (MANA)

Database

• UniProt: http://www.uniprot.org/uniprot/O00754.html
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=4125
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:4125
• OMIM: https://mirror.omim.org/entry/248500
• OMIM: https://mirror.omim.org/entry/609458