Alpha-1-antitrypsin: Difference between revisions

From Proteopedia
Jump to navigation Jump to search
No edit summary
No edit summary
Line 1: Line 1:
{{STRUCTURE_1atu |  PDB=1atu1ezxwd.pdb  |  SCENE=User:Daniel_Seeman/Alpha-1-antitrypsin/437437437437/1}}
{{STRUCTURE_1atu |  PDB=1atu1ezxwd.pdb  |  SCENE=User:Daniel_Seeman/Alpha-1-antitrypsin/437437437437/1}}
'''Alpha-1-antitrypsin''' (also known as α1-antitrypsin or A1AT) is an inhibitor of [[Elastase]] and [[Trypsin]].  It is a member of the '''Ser'''ine '''P'''rotease '''I'''nhibitor ([[:Category:Serpin|Serpin]]) family, and as such undergoes a conformational change where the substrate protein associates with a loop region on A1AT causing that loop to become ordered as a Beta Strand<ref name="nature_paper">''Nature'' '''455''', 1189-1190 (30 October 2008)</ref>.  In this case Trypsin (the substrate) is inhibited when a covalent bond is formed to A1AT through the newly formed Beta region<ref name="nature_paper" />.  Once bound covalently to its substrate the stability of the A1AT complex goes up drastically, making it essentially "a molecular mousetrap"<ref name="nature_paper" />.  With A1AT, as with most members of the Serpin family, the transition from inactive precursor protein to active complex comes after a cleavage event<ref name="nature_paper" />.  Shown <scene name='User:Daniel_Seeman/Alpha-1-antitrypsin/437437437437/1'>on the right</scene> is a morph, generated by the <span class="plainlinks">[http://molmovdb.mbb.yale.edu/molmovdb/morph/ Yale Morph Server]</span> that shows A1AT going from its inactive form, to the conformation in which it is bound to Trypsin (also shown in the same animation)<ref>The <span class="plainlinks">[http://molmovdb.mbb.yale.edu/molmovdb/morph/ Yale Morph Server]</span></ref>.  
'''Alpha-1-antitrypsin''' (also known as α1-antitrypsin or A1AT) is an inhibitor of [[Elastase]] and [[Trypsin]].  It is a member of the '''Ser'''ine '''P'''rotease '''I'''nhibitor ([[:Category:Serpin|Serpin]]) family, and as such undergoes a conformational change where the substrate protein associates with a loop region on A1AT causing that loop to become ordered as a Beta Strand<ref name="nature_paper">''Nature'' '''455''', 1189-1190 (30 October 2008)</ref>.  In this case Trypsin (the substrate) is inhibited when a covalent bond is formed to A1AT through the newly formed Beta region<ref name="nature_paper" />.  Once bound covalently to its substrate the stability of the A1AT complex goes up drastically, making it an effective "molecular mousetrap"<ref name="nature_paper" />.  With A1AT, as with most members of the Serpin family, the transition from inactive precursor protein to active complex comes after a cleavage event<ref name="nature_paper" />.  Shown <scene name='User:Daniel_Seeman/Alpha-1-antitrypsin/437437437437/1'>on the right</scene> is a morph, generated by the <span class="plainlinks">[http://molmovdb.mbb.yale.edu/molmovdb/morph/ Yale Morph Server]</span> that shows A1AT going from its inactive form, to the conformation in which it is bound to Trypsin (also shown in the same animation)<ref>The <span class="plainlinks">[http://molmovdb.mbb.yale.edu/molmovdb/morph/ Yale Morph Server]</span></ref>.  


=== Role in disease ===
=== Role in disease ===

Revision as of 23:24, 2 December 2008

Drag the structure with the mouse to rotate
1atu, resolution 2.70Å ()
Resources: FirstGlance, OCA, RCSB, PDBsum
Coordinates: save as pdb, mmCIF, xml


Alpha-1-antitrypsin (also known as α1-antitrypsin or A1AT) is an inhibitor of Elastase and Trypsin. It is a member of the Serine Protease Inhibitor (Serpin) family, and as such undergoes a conformational change where the substrate protein associates with a loop region on A1AT causing that loop to become ordered as a Beta Strand[1]. In this case Trypsin (the substrate) is inhibited when a covalent bond is formed to A1AT through the newly formed Beta region[1]. Once bound covalently to its substrate the stability of the A1AT complex goes up drastically, making it an effective "molecular mousetrap"[1]. With A1AT, as with most members of the Serpin family, the transition from inactive precursor protein to active complex comes after a cleavage event[1]. Shown is a morph, generated by the Yale Morph Server that shows A1AT going from its inactive form, to the conformation in which it is bound to Trypsin (also shown in the same animation)[2].

Role in diseaseRole in disease

Mutations of MET358 to ARG can lead to a change in specificity in the Elastase binding pocket, essentially turning the M358R mutant of A1AT into a Thrombin inhibitor by generating specificity for this new substrate. This drop in Thrombin levels can lead to hemorrhaging. [3]

ScenesScenes

See AlsoSee Also

ReferencesReferences

  1. 1.0 1.1 1.2 1.3 Nature 455, 1189-1190 (30 October 2008)
  2. The Yale Morph Server
  3. Biochemistry, Fifth Edition, p.289.

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

Daniel Seeman, Michal Harel, Alexander Berchansky, Joel L. Sussman