Plasmin

Plasminogen

PDB rendering based on 1b2i.
Identifiers
Symbols PLG; DKFZp779M0222
External IDs OMIM: 173350 MGI: 97620 HomoloGene: 55452 GeneCards: PLG Gene
EC number 3.4.21.7
RNA expression pattern
More reference expression data
Orthologs
Species Human Mouse
Entrez 5340 18815
Ensembl ENSG00000122194 ENSMUSG00000059481
UniProt P00747 Q3V1T9
RefSeq (mRNA) NM_000301.3 NM_008877.3
RefSeq (protein) NP_000292.1 NP_032903.3
Location (UCSC) Chr 6:
161.12 – 161.17 Mb		 Chr 17:
12.57 – 12.61 Mb
PubMed search [1] [2]

Plasmin is an important enzyme (EC 3.4.21.7) present in blood that degrades many blood plasma proteins, most notably, fibrin clots. The degradation of fibrin is termed fibrinolysis. In humans, the plasmin protein is encoded by the PLG gene.[1]

Contents

Function

Plasmin is a serine protease that acts to dissolve fibrin blood clots. Apart from fibrinolysis, plasmin proteolyses proteins in various other systems: It activates collagenases, some mediators of the complement system and weakens the wall of the Graafian follicle (leading to ovulation). It cleaves fibrin, fibronectin, thrombospondin, laminin, and von Willebrand factor. Plasmin, like trypsin, belongs to the family of serine proteases.

Plasmin is released as a zymogen called plasminogen (PLG) from the liver into the systemic circulation. Plasminogen is converted into active plasmin by a variety of enzymes, including tissue plasminogen activator (tPA), urokinase plasminogen activator (uPA), kallikrein, and factor XII (Hageman factor). Fibrin is a cofactor for plasminogen activation by tissue plasminogen activator. Urokinase plasminogen activator receptor (uPAR) is a cofactor for plasminogen activation by urokinase plasminogen activator. The conversion of plasminogen to plasmin involves the cleavage of the peptide bond between Arg-560 and Val-561.[1][2][3]

Plasmin cleavage produces angiostatin.

Pathology

Deficiency in plasmin may lead to thrombosis, as clots are not degraded adequately. Plasminogen deficiency in mice leads to defective liver repair,[4] defective wound healing, reproductive abnormalities.

In human, a rare disorder called plasminogen deficiency type I (OMIM 217090) is caused by mutations of the PLG gene and is often manifested by ligneous conjunctivitis.

Interactions

Plasmin has been shown to interact with Thrombospondin 1,[5][6] Alpha 2-antiplasmin[7][8] and IGFBP3.[9]

References

  1. ^ a b "Entrez Gene: plasminogen". http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=5340. 
  2. ^ Miyata T, Iwanaga S, Sakata Y, Aoki N (October 1982). "Plasminogen Tochigi: inactive plasmin resulting from replacement of alanine-600 by threonine in the active site". Proc. Natl. Acad. Sci. U.S.A. 79 (20): 6132–6. doi:10.1073/pnas.79.20.6132. PMC 347073. PMID 6216475. http://www.pnas.org/cgi/pmidlookup?view=long&pmid=6216475. 
  3. ^ Forsgren M, Råden B, Israelsson M, Larsson K, Hedén LO (March 1987). "Molecular cloning and characterization of a full-length cDNA clone for human plasminogen". FEBS Lett. 213 (2): 254–60. doi:10.1016/0014-5793(87)81501-6. PMID 3030813. http://linkinghub.elsevier.com/retrieve/pii/0014-5793(87)81501-6. 
  4. ^ Jorge A. Bezerra, Thomas H. Bugge, Hector Melin-Aldana, Gregg Sabla, Keith W. Kombrinck, David P. Witte, and Jay L. Degen (December 21, 1999). Plasminogen deficiency leads to impaired remodeling after a toxic injury to the liver. Proceedings of the National Academy of Sciences of the United States of America. PMID 10611352. http://www.pnas.org/content/96/26/15143.short. Retrieved June 03, 2011. 
  5. ^ Silverstein, R L; Leung L L, Harpel P C, Nachman R L (Nov. 1984). "Complex formation of platelet thrombospondin with plasminogen. Modulation of activation by tissue activator". J. Clin. Invest. (UNITED STATES) 74 (5): 1625–33. doi:10.1172/JCI111578. ISSN 0021-9738. PMC 425339. PMID 6438154. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=425339. 
  6. ^ DePoli, P; Bacon-Baguley T, Kendra-Franczak S, Cederholm M T, Walz D A (Mar. 1989). "Thrombospondin interaction with plasminogen. Evidence for binding to a specific region of the kringle structure of plasminogen". Blood (UNITED STATES) 73 (4): 976–82. ISSN 0006-4971. PMID 2522013. 
  7. ^ Wiman, B; Collen D (Sep. 1979). "On the mechanism of the reaction between human alpha 2-antiplasmin and plasmin". J. Biol. Chem. (UNITED STATES) 254 (18): 9291–7. ISSN 0021-9258. PMID 158022. 
  8. ^ Shieh, B H; Travis J (May. 1987). "The reactive site of human alpha 2-antiplasmin". J. Biol. Chem. (UNITED STATES) 262 (13): 6055–9. ISSN 0021-9258. PMID 2437112. 
  9. ^ Campbell, P G; Durham S K, Suwanichkul A, Hayes J D, Powell D R (Aug. 1998). "Plasminogen binds the heparin-binding domain of insulin-like growth factor-binding protein-3". Am. J. Physiol. (UNITED STATES) 275 (2 Pt 1): E321–31. ISSN 0002-9513. PMID 9688635. 

Further reading

External links

This article incorporates text from the United States National Library of Medicine, which is in the public domain.

Serum globulins
Other
Other globulins
Albumins
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see also disorders of globin and globulin proteins
B proteins: BY STRUCTURE: membrane, globular (en, ca, an), fibrous
Coagulation factors
Coagulation inhibitors
Thrombolysis/fibrinolysis
Plasmin · tPA/urokinase · PAI-1/2 · α2-AP · α2-macroglobulin · TAFI

M: MYL

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