• Purity

  >75%, by SDS-PAGE under reducing conditions and visualized by silver stain

• Endotoxin Level

  <0.10 EU per 1 μg of the protein by the LAL method.  

• Activity

  Measured by its binding ability in a functional ELISA. When Recombinant Human alpha     ₂‑Macroglobulin-like1 is immobilized at 2 μg/mL (100 µL/well), the concentration of Recombinant Human LRP‑1 Cluster II Fc Chimera (Catalog # ) that produces 50% of the optimal binding response is approximately 1‑5 μg/mL.

• Source

  Human embryonic kidney cell, HEK293-derived Glu18-Glu1454, with a C-terminal 6-His tag

• Accession #

• N-terminal Sequence    
  Analysis

  Starts at Glu18

• Predicted Molecular Mass

  160 kDa

• SDS-PAGE

  155‑175 kDa, reducing conditions

Background: alpha 2-Macroglobulin-like 1/A2ML1

alpha   ₂-Macroglobulin like-1 (A2ML1) is an approximately 180 kDa secreted glycoprotein that is structurally and functionally similar to alpha   ₂‑Macroglobulin (A2M) (1). Mature human A2ML1 shares 40% amino acid sequence identity with human A2M. It functions as a broad spectrum protease inhibitor with activity toward chymotrypsin, papain, thermolysin, and subtilisin A (2). Like A2M, A2ML1 binds to proteases covalently and contains a bait region (2). When the bait region is cleaved by a targeted protease, A2M undergoes a conformational change which blocks the protease’s active site and also promotes A2M clearance from the circulation (1). In contrast to the dimeric and tetrameric A2M, A2ML1 is secreted as a monomer (2, 3). A2ML1 is expressed in epidermis, testis, thymus, and placenta (2). It binds to Kallikrein 7, a protease that regulates epidermal desquamation by disrupting corneocyte adhesion (2, 4). The C‑terminal domain of A2ML1 mediates binding to LRP1 on the surface of macrophages followed by endocytosis (5). A2M has a similar receptor‑binding domain which is responsible for A2M interactions with LRP1 (6). A2ML1 is also known as the keratinocyte p170 autoantigen in the skin disease paraneoplastic pemphigus (7). During zebrafish development, an A2ML1-like protein is required for liver formation (8).

• References:

1. Sottrup-Jensen, L. (1989) J. Biol. Chem. 264:11539.

2. Galliano, M.-F. et al. (2006) J. Biol. Chem. 281:5780.

3. Gettins, P.G. et al. (1995) J. Biol. Chem. 270:14160.

4. Caubet, C. et al. (2004) J. Invest. Dermatol. 122:1235.

5. Galliano, M.-F. et al. (2008) PLoS ONE 3:e2729.

6. Sottrup-Jensen, L. et al. (1986) FEBS Lett. 205:20.

7. Schepens, I. et al. (2010) PLoS ONE 5:e12250.

8. Hong, S.-K. and I.B. Dawid (2008) PLoS ONE 3:e3736.

• Entrez Gene IDs:

  144568 (Human)

• Alternate Names:

  A2ML1; alpha 2Macroglobulin like 1; alpha 2-Macroglobulin-like 1; alpha-2-macroglobulin-like 1; alpha-2-macroglobulin-like protein 1; C3 and PZP-like, alpha-2-macroglobulin domain containing 9; CPAMD9