mannan-binding lectin serine protease 2; MBL-associated serine protease 2; mannose-binding protein-associated serine protease 2; MASP-2; contains: mannan-binding lectin serine protease 2 A chain; mannan-binding lectin serine protease 2 B chain (MASP2)

Function

• serine protease
• role in activation of the complement system via mannose-binding lectin
• after activation by auto-catalytic cleavage it cleaves complement-C2 & complement-C4, leading to their activation & to the formation of C3 convertase
• selective cleavage after Arg-223 in complement-C2 (-Ser-Leu-Gly-Arg-|-Lys-Ile-Gln-Ile) & after Arg-76 in complement-C4 (-Gly-Leu-Gln-Arg-|-Ala-Leu-Glu-Ile)
• iron & 2-oxoglutarate dependent 3-hydroxylation of Asp & Asn is (R) stereospecific within EGF domains
• activated by cleavage after Arg-444
• uncleaved zymogen is inactive towards synthetic substrates, but has sufficient activity to effect autocatalytic cleavage
• binds MBL2
• isoform 2 binds to MASP1
• binds SERPING1
• dimerization & MBL2 binding requires Ca+2

Structure

• homodimer; disulfide-linked
• belongs to the peptidase S1 family
• contains 2 CUB domains
• contains 1 EGF-like domain
• contains 1 peptidase S1 domain
• contains 2 Sushi (CCP/SCR) domains

Compartment

secreted

Alternative splicing

named isoforms=2

Expression

plasma

Pathology

• defects in MASP2 are the cause of MASP2 deficiency

More general terms

• serine protease
• glycoprotein
• Ca+2 binding protein
• secreted protein

Additional terms

• lectin
• mannan (mannosan)
• mannose

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=10747
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:10747
• OMIM: https://mirror.omim.org/entry/605102
• OMIM: https://mirror.omim.org/entry/613791
• UniProt: http://www.uniprot.org/uniprot/O00187.html