Protein Domain : Alpha-2-macroglobulin, TED domain IPR041813

Type	Domain
Description	This entry represents the TED (thiol ester-containing domain) domain found in alpha2-macroglobulin (alpha (2)-M) and related proteins [ , , ]. This domain has a short highly conserved region of proteinase-binding alpha-macro-globulins containing the cysteine and a glutamine of a thiol-ester bond that is cleaved at the moment of proteinase binding, and mediates the covalent binding of the alpha-macro-globulin to the proteinase. The GCGEQ motif is highly conserved [, , , ]. Proteins containing this domain also include pregnancy zone protein (PZP). Alpha(2)-M and PZP are broadly specific proteinase inhibitors. Alpha (2)-M is a major carrier protein in serum. The structural thioester of alpha (2)-M, is involved in the immobilization and entrapment of proteases. PZP is a trace protein in the plasma of non-pregnant females and males which is elevated in pregnancy. Alpha (2)-M and PZP bind to placental protein-14 and may modulate its activity in T-cell growth and cytokine production contributing to fetal survival. It has been suggested that thioester bond cleavage promotes the binding of PZP and alpha (2)-M to the CD91 receptor clearing them from circulation [, , ].
Short Name	A2M_TED