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mannan-binding lectin serine protease 1; complement factor MASP-3; complement-activating component of Ra-reactive factor; mannose-binding lectin-associated serine protease 1; MASP-1; mannose-binding protein-associated serine protease; Ra-reactive factor serine protease p100; RaRF; serine protease 5; contains: mannan-binding lectin serine protease 1 heavy chain; mannan-binding lectin serine protease 1 light chain (MASP1, CRARF, CRARF1, PRSS5)
Function:
- functions in the lectin pathway of complement, which performs a key role in innate immunity by recognizing pathogens through patterns of sugar moieties & neutralizing them
- the lectin pathway is triggered upon binding of mannan-binding lectin & ficolins to sugar moieties which leads to activation of the associated proteases MASP1 & MASP2
- functions as an endopeptidase & may activate MASP2 or complement-C2 or directly activate complement-C3
- isoform 2 may have an inhibitory effect on the activation of the lectin pathway of complement or may cleave IGFBP5
- inhibited by SERPING1 & A2M
- iron & 2-oxoglutarate dependent 3-hydroxylation of Asp & Asp is (R) stereospecific within EGF domains
- some N-linked glycan are of the complex-type
- autoproteolytic processing of the proenzyme produces the active enzyme composed of a heavy & the light chain held together by a disulfide bond
- isoform 1 but not isoform 2 is activated through autoproteolytic processing
- interacts with the oligomeric lectins MBL2, FCN2 & FCN3; triggers the lectin pathway of complement through activation of complement-C3
- interacts with SERPING1
Kinetic parameters:
- KM=0.10 mM for Ac-Gly-Lys-OMe (at 30 degrees celsius)
- KM=310 uM for Bz-Arg-OEt (at 30 degrees celsius)
- KM=4.8 uM for C2 (at 37 degrees celsius)
Structure:
- homodimer
- N-glycosylated
- glycosylated on Asn-533 & Asn-599
- 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=4
Expression:
- protein of the plasma which is primarily expressed by liver
Pathology:
- defects in MASP1 are the cause of 3MC syndrome type 1
Polymorphism:
- variant in position: 497:H->Y (in 3MC1)
- variant in position: 630:C->R (in 3MC1)
- variant in position: 666:G->E (in 3MC1)
Related
lectin
mannan (mannosan)
mannose
General
Ca+2 binding protein
glycoprotein
secreted protein
serine protease
Properties
SIZE: entity length = 699 aa
MW = 79 kD
COMPARTMENT: extracellular compartment
MOTIF: signal sequence {1-19}
FCN2 interaction {20-278}
MOTIF: Homodimerization {20-184}
MBL2 interaction {20-184}
CUB domain {20-138}
N-glycosylation site {N49}
Ca+2-binding site
SITE: 68-68
cysteine residue {C73}
MODIFICATION: cysteine residue {C91}
Ca+2-binding site
SITE: 76-76
cysteine residue {C91}
MODIFICATION: cysteine residue {C73}
Ca+2-binding site
SITE: 121-121
Ca+2-binding site
SITE: 123-123
EGF domain {139-182}
Ca+2-binding site
SITE: 139-139
Ca+2-binding site
SITE: 140-140
Ca+2-binding site
SITE: 142-142
cysteine residue {C143}
MODIFICATION: cysteine residue {C157}
cysteine residue {C153}
MODIFICATION: cysteine residue {C166}
cysteine residue {C157}
MODIFICATION: cysteine residue {C143}
Ca+2-binding site
SITE: 159-159
Ca+2-binding site
SITE: 160-160
Ca+2-binding site
SITE: 163-163
cysteine residue {C166}
MODIFICATION: cysteine residue {C153}
cysteine residue {C168}
MODIFICATION: cysteine residue {C181}
N-glycosylation site {N178}
cysteine residue {C181}
MODIFICATION: cysteine residue {C168}
CUB domain {185-297}
MOTIF: cysteine residue {C185}
MODIFICATION: cysteine residue {C212}
cysteine residue {C212}
MODIFICATION: cysteine residue {C185}
Ca+2-binding site
SITE: 235-235
cysteine residue {C242}
MODIFICATION: cysteine residue {C260}
Ca+2-binding site
SITE: 245-245
cysteine residue {C260}
MODIFICATION: cysteine residue {C242}
Ca+2-binding site
SITE: 282-282
Ca+2-binding site
SITE: 284-284
Sushi domain {299-364}
MOTIF: cysteine residue {C301}
MODIFICATION: cysteine residue {C349}
cysteine residue {C329}
MODIFICATION: cysteine residue {C362}
cysteine residue {C349}
MODIFICATION: cysteine residue {C301}
cysteine residue {C362}
MODIFICATION: cysteine residue {C329}
Sushi domain {365-434}
MOTIF: cysteine residue {C367}
MODIFICATION: cysteine residue {C414}
N-glycosylation site {N385}
cysteine residue {C397}
MODIFICATION: cysteine residue {C432}
N-glycosylation site {N407}
cysteine residue {C414}
MODIFICATION: cysteine residue {C367}
cysteine residue {C432}
MODIFICATION: cysteine residue {C397}
cysteine residue {C436}
MODIFICATION: cysteine residue {C-INTERCHAIN}
proteolytic site {448-449}
S1 domain {449-696}
MOTIF: cysteine residue {C475}
MODIFICATION: cysteine residue {C491}
histidine residue {H490}
cysteine residue {C491}
MODIFICATION: cysteine residue {C475}
aspartate residue {D552}
cysteine residue {C614}
MODIFICATION: cysteine residue {C631}
cysteine residue {C631}
MODIFICATION: cysteine residue {C614}
cysteine residue {C642}
MODIFICATION: cysteine residue {C672}
serine residue {S646}
cysteine residue {C672}
MODIFICATION: cysteine residue {C642}
Database Correlations
OMIM correlations
UniProt P48740
PFAM correlations
Entrez Gene 5648
Kegg hsa:5648
References
UniProt :accession P48740