mannose-binding protein C; MBP-C; MBP1; mannan-binding protein; mannose-binding lectin (MBL2, MBL)

Function

• role in host defense against pathogens, by activating the classical complement pathway independently of antibody (via mannose-binding lectin pathway)
• binds mannose & N-acetylglucosamine (Ca+2-dependent) expressed on the surface of certain pathogens
• reported to react with acapsular gram-positive & gram-negative bacteria, mycobacteria, viruses, yeast, parasites & protozoa
• upon recognition of antigen, MBL2 adopts a conformational change that leads to activation of serine proteases MASP1 & MASP2
• interacts with MASP1 & MASP2 (Ca+2-dependent)

Structure

• oligomeric complex of 6 set of homotrimers
• contains 1 C-type lectin domain
• contains 1 collagen-like domain

Expression

• formed in the liver
• present in plasma at about 1.5 ug/mL

Pathology

• there is an association between low levels of MBL2 & a defect of opsonization which results in susceptibility to frequent & chronic infections
• genetic variations in MBL2 are associated with susceptibility to hepatitis B virus infection

Laboratory

• MBL2 gene mutation

Comparative biology

• found in all mammals

More general terms

• collectin
• Ca+2 binding protein

Additional terms

• mannan-binding lectin pathway (MLB pathway)

Database

• UniProt: http://www.uniprot.org/uniprot/P11226.html
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=4153
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:4153
• OMIM: https://mirror.omim.org/entry/154545
• OMIM: https://mirror.omim.org/entry/610424