plasminogen; contains: plasmin heavy chain A; activation peptide; angiostatin; plasmin light chain B (PLG)
Jump to navigation
Jump to search
Function
- plasminogen contains, in addition to binding site(s) for fibrin, site(s) for binding to the surface of platelets
- plasmin formed of the surface of platelets has the ability to degrade glycoprotein Ib & glycoprotein IIb/IIIa & the vWF/VIII complex disrupting adhesion & aggregation of platelets
- plasminogen also binds to the surface of endothelial cells
- release of tissue plasminogen activator by endothelial cells, results in generation of plasmin at the surface of intact endothelium, limiting fibrin formation to the site of vascular injury
- converted into plasmin by plasminogen activators, both plasminogen & its activator being bound to fibrin
- activated with catalytic amounts of streptokinase
- in the presence of plaminogen activator inhibitor, activation involves only cleavage after Arg-580, yielding two chains held together by two disulfide bonds.
- in the absence of plaminogen activator inhibitor, activation involves additionally the removal of the activation peptide
- interacts with CSPG4 & AMOT
- interacts (via the Kringle domains) with HRG
- interaction tethers PLG to the cell surface & enhances its activation (putative)
Structure
- N-linked glycan contains N-acetyllactosamine & sialic acid
- O-linked glycans consist of gal-galNAc disaccharide modified with up to 2 sialic acid residues (microheterogeneity)
- Kringle domains mediate interaction with CSPG4
- belongs to the peptidase S1 family, plasminogen subfamily
- contains 5 kringle domains
- contains 1 PAN domain
- contains 1 peptidase S1 domain
Compartment
- secreted.
- locates to the cell surface where it is proteolytically cleaved to produce the active plasmin
- interaction with HRG tethers it to the cell surface
Expression
- present in plasma & many other extracellular fluids.
- synthesized in the liver
Pathology
- defects in plasminogen are a cause of hypercoagulability
- defects in plasminogen are the cause of plasminogen deficiency
More general terms
- protein precursor
- coagulation factor
- fibrinolytic agent (thrombolytic agent)
- phosphoprotein
- glycoprotein
Additional terms
References
- ↑ UniProt http://www.uniprot.org/uniprot/P00747.html
- ↑ Wikipedia; Note: plasmin entry http://en.wikipedia.org/wiki/plasmin
- ↑ SeattleSNPs http://pga.gs.washington.edu/data/plg/
- ↑ Clinical Diagnosis and Management by Laboratory Methods, 18th ed, J.B. Henry (ed), W.B. Saunders, Philadelphia, PA, 1991 pg 739
- ↑ Fibrinolysis, Thrombosis, & Hemostasis: Concepts, Perspectives, and Clinical Applications. S Sherry, Lea & Febiger, Philadelphia, 1992, pg 15
Database
- Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=5340
- Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:5340
- OMIM: https://mirror.omim.org/entry/173350
- OMIM: https://mirror.omim.org/entry/188050
- OMIM: https://mirror.omim.org/entry/217090
- UniProt: http://www.uniprot.org/uniprot/P00747.html