1iz2

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1iz2, resolution 2.20Å ()
Ligands:
Resources: FirstGlance, OCA, RCSB, PDBsum
Coordinates: save as pdb, mmCIF, xml


Contents

Interactions causing the kinetic trap in serpin protein folding

Publication Abstract from PubMed

Conformational transition is fundamental to the mechanism of functional regulation in proteins, and serpins (serine protease inhibitors) can provide insight into this process. Serpins are metastable in their native forms, and they ordinarily undergo conformational transition to a stable state only when they form a tight complex with target proteases. The metastable native form is thus considered to be a kinetically trapped folding intermediate. We sought to understand the nature of the serpin kinetic trap as a step toward discovering how conformational transition is regulated. We found that mutations of the B/C beta-barrel of native alpha(1)-antitrypsin, a prototypical serpin, allowed conversion of the molecule into a more stable state. A 2.2 A resolution crystal structure of the stable form (PDB code, ) showed that the reactive site loop is inserted into an A beta-sheet, as in the latent plasminogen activator inhibitor-1. Mutational analyses suggest strongly that interactions not found in the final stable form cause the kinetic trap in serpin protein folding.

Interactions causing the kinetic trap in serpin protein folding., Im H, Woo MS, Hwang KY, Yu MH, J Biol Chem. 2002 Nov 29;277(48):46347-54. Epub 2002 Sep 18. PMID:12244055

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

Disease

[A1AT_HUMAN] Defects in SERPINA1 are the cause of alpha-1-antitrypsin deficiency (A1ATD) [MIM:613490]. A disorder whose most common manifestation is emphysema, which becomes evident by the third to fourth decade. A less common manifestation of the deficiency is liver disease, which occurs in children and adults, and may result in cirrhosis and liver failure. Environmental factors, particularly cigarette smoking, greatly increase the risk of emphysema at an earlier age.[1][2][3]

Function

[A1AT_HUMAN] Inhibitor of serine proteases. Its primary target is elastase, but it also has a moderate affinity for plasmin and thrombin. Irreversibly inhibits trypsin, chymotrypsin and plasminogen activator. The aberrant form inhibits insulin-induced NO synthesis in platelets, decreases coagulation time and has proteolytic activity against insulin and plasmin.[:][4][5] Short peptide from AAT: reversible chymotrypsin inhibitor. It also inhibits elastase, but not trypsin. Its major physiological function is the protection of the lower respiratory tract against proteolytic destruction by human leukocyte elastase (HLE).[:][6][7]

About this Structure

1iz2 is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA.

See Also

Reference

  • Im H, Woo MS, Hwang KY, Yu MH. Interactions causing the kinetic trap in serpin protein folding. J Biol Chem. 2002 Nov 29;277(48):46347-54. Epub 2002 Sep 18. PMID:12244055 doi:10.1074/jbc.M207682200
  1. Seyama K, Nukiwa T, Takabe K, Takahashi H, Miyake K, Kira S. Siiyama (serine 53 (TCC) to phenylalanine 53 (TTC)). A new alpha 1-antitrypsin-deficient variant with mutation on a predicted conserved residue of the serpin backbone. J Biol Chem. 1991 Jul 5;266(19):12627-32. PMID:1905728
  2. Holmes MD, Brantly ML, Fells GA, Crystal RG. Alpha 1-antitrypsin Wbethesda: molecular basis of an unusual alpha 1-antitrypsin deficiency variant. Biochem Biophys Res Commun. 1990 Aug 16;170(3):1013-20. PMID:2390072
  3. Graham A, Kalsheker NA, Bamforth FJ, Newton CR, Markham AF. Molecular characterisation of two alpha-1-antitrypsin deficiency variants: proteinase inhibitor (Pi) Null(Newport) (Gly115----Ser) and (Pi) Z Wrexham (Ser-19----Leu). Hum Genet. 1990 Oct;85(5):537-40. PMID:2227940
  4. Tanaka N, Sekiya S, Takamizawa H, Kato N, Moriyama Y, Fujimura S. Characterization of a 54 kDa, alpha 1-antitrypsin-like protein isolated from ascitic fluid of an endometrial cancer patient. Jpn J Cancer Res. 1991 Jun;82(6):693-700. PMID:1906855
  5. Niemann MA, Narkates AJ, Miller EJ. Isolation and serine protease inhibitory activity of the 44-residue, C-terminal fragment of alpha 1-antitrypsin from human placenta. Matrix. 1992 Jun;12(3):233-41. PMID:1406456
  6. Tanaka N, Sekiya S, Takamizawa H, Kato N, Moriyama Y, Fujimura S. Characterization of a 54 kDa, alpha 1-antitrypsin-like protein isolated from ascitic fluid of an endometrial cancer patient. Jpn J Cancer Res. 1991 Jun;82(6):693-700. PMID:1906855
  7. Niemann MA, Narkates AJ, Miller EJ. Isolation and serine protease inhibitory activity of the 44-residue, C-terminal fragment of alpha 1-antitrypsin from human placenta. Matrix. 1992 Jun;12(3):233-41. PMID:1406456

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