Serpin

Serpin (serine protease inhibitor)
A serpin (white) with its 'reactive centre loop' (blue) bound to a protease (grey). Once the protease attempts catalysis it will be irreversibly inhibited. (PDB: 1K9O​)
Identifiers
SymbolSerpin, SERPIN (root symbol of family)
PfamPF00079
InterProIPR000215
PROSITEPDOC00256
SCOP21hle / SCOPe / SUPFAM
CDDcd00172
Available protein structures:
Pfam  structures / ECOD  
PDBRCSB PDB; PDBe; PDBj
PDBsumstructure summary
PDB1m37A:1-378 1hleB:349-379 1jrrA:1-415

1by7A:1-415 1ovaA:1-385 1uhgA:1-385 1jtiB:1-385 1attB:77-433 1nq9L:76-461 1oyhI:76-461 1e03L:76-461 1e05I:76-461 1br8L:76-461 1r1lL:76-461 1lk6L:76-461 1antL:76-461 2behL:76-461 1dzhL:76-461 1athA:78-461 1tb6I:76-461 2antI:76-461p 1dzgI:76-461 1azxL:76-461 1jvqI:76-461 1sr5A:76-461 1e04I:76-461 1xqgA:1-375 1xu8B:1-375 1wz9B:1-375 1xqjA:1-375 1c8oA:1-300 1m93A:1-55 1f0cA:1-305 1k9oI:18-392 1sek :18-369 1atu :45-415 1ezxB:383-415 8apiA:43-382 1qmbA:49-376 1iz2A:43-415 1oo8A:43-415 1d5sB:378-415 7apiA:44-382 1qlpA:43-415 1ophA:43-415 1kct :44-415 2d26A:43-382 9apiB:383-415 1psi :47-415 1hp7A:43-415 3caaA:50-383 1qmnA:43-420 4caaB:390-420 2achA:47-383 1as4A:48-383 1yxaB:42-417 1lq8F:376-406 2paiB:374-406 1paiB:374-406 1jmoA:119-496 1jmjA:119-496 1oc0A:25-402 1dvnA:25-402 1b3kD:25-402 1dvmD:25-402 1a7cA:25-402 1c5gA:25-402 1db2B:26-402 9paiA:25-402 1lj5A:25-402 1m6qA:138-498 1jjoD:101-361

1imvA:49-415

Serpins are a superfamily of proteins with similar structures that were first identified for their protease inhibition activity and are found in all kingdoms of life.[1][2] The acronym serpin was originally coined because the first serpins to be identified act on chymotrypsin-like serine proteases (serine protease inhibitors).[3][4][5] They are notable for their unusual mechanism of action, in which they irreversibly inhibit their target protease by undergoing a large conformational change to disrupt the target's active site.[6][7] This contrasts with the more common competitive mechanism for protease inhibitors that bind to and block access to the protease active site.[8][9]

Protease inhibition by serpins controls an array of biological processes, including coagulation and inflammation, and consequently these proteins are the target of medical research.[10] Their unique conformational change also makes them of interest to the structural biology and protein folding research communities.[7][8] The conformational-change mechanism confers certain advantages, but it also has drawbacks: serpins are vulnerable to mutations that can result in serpinopathies such as protein misfolding and the formation of inactive long-chain polymers.[11][12] Serpin polymerisation not only reduces the amount of active inhibitor, but also leads to accumulation of the polymers, causing cell death and organ failure.[10]

Although most serpins control proteolytic cascades, some proteins with a serpin structure are not enzyme inhibitors, but instead perform diverse functions such as storage (as in egg whiteovalbumin), transport as in hormone carriage proteins (thyroxine-binding globulin, cortisol-binding globulin) and molecular chaperoning (HSP47).[9] The term serpin is used to describe these members as well, despite their non-inhibitory function, since they are evolutionarily related.[1]

  1. ^ a b Cite error: The named reference Silverman_2001 was invoked but never defined (see the help page).
  2. ^ Spence MA, Mortimer MD, Buckle AM, Minh BQ, Jackson CJ (June 2021). Echave J (ed.). "A Comprehensive Phylogenetic Analysis of the Serpin Superfamily". Molecular Biology and Evolution. 38 (7): 2915–2929. doi:10.1093/molbev/msab081. PMC 8233489. PMID 33744972.
  3. ^ Carrell RW, Boswell DR (1986). "Serpins: the superfamily of plasma serine proteinase inhibitors". In Barrett AJ, Salvesen G (eds.). Proteinase Inhibitors. Research monographs in cell and tissue physiology. Vol. 12. Amsterdam: Elsevier Science Publishers BV. pp. 403–420. ISBN 0-444-80763-2.
  4. ^ Silverman GA, Whisstock JC, Bottomley SP, Huntington JA, Kaiserman D, Luke CJ, Pak SC, Reichhart JM, Bird PI (August 2010). "Serpins flex their muscle: I. Putting the clamps on proteolysis in diverse biological systems". The Journal of Biological Chemistry. 285 (32): 24299–24305. doi:10.1074/jbc.R110.112771. PMC 2915665. PMID 20498369.
  5. ^ Whisstock JC, Silverman GA, Bird PI, Bottomley SP, Kaiserman D, Luke CJ, Pak SC, Reichhart JM, Huntington JA (August 2010). "Serpins flex their muscle: II. Structural insights into target peptidase recognition, polymerization, and transport functions". The Journal of Biological Chemistry. 285 (32): 24307–24312. doi:10.1074/jbc.R110.141408. PMC 2915666. PMID 20498368.
  6. ^ Huntington JA, Read RJ, Carrell RW (October 2000). "Structure of a serpin-protease complex shows inhibition by deformation". Nature. 407 (6806): 923–926. Bibcode:2000Natur.407..923H. doi:10.1038/35038119. PMID 11057674. S2CID 205009937.
  7. ^ a b Gettins PG (December 2002). "Serpin structure, mechanism, and function". Chemical Reviews. 102 (12): 4751–4804. doi:10.1021/cr010170. PMID 12475206.
  8. ^ a b Whisstock JC, Bottomley SP (December 2006). "Molecular gymnastics: serpin structure, folding and misfolding". Current Opinion in Structural Biology. 16 (6): 761–768. doi:10.1016/j.sbi.2006.10.005. PMID 17079131.
  9. ^ a b Cite error: The named reference Law_2006 was invoked but never defined (see the help page).
  10. ^ a b Stein PE, Carrell RW (February 1995). "What do dysfunctional serpins tell us about molecular mobility and disease?". Nature Structural Biology. 2 (2): 96–113. doi:10.1038/nsb0295-96. PMID 7749926. S2CID 21223825.
  11. ^ Janciauskiene SM, Bals R, Koczulla R, Vogelmeier C, Köhnlein T, Welte T (August 2011). "The discovery of α1-antitrypsin and its role in health and disease". Respiratory Medicine. 105 (8): 1129–1139. doi:10.1016/j.rmed.2011.02.002. PMID 21367592.
  12. ^ Cite error: The named reference Carrell_1997 was invoked but never defined (see the help page).